DISCOUNT DETECTIVE

Discount Detective

Ignore the percentage. Compare with what you actually paid before.

1+1, 2+1, markdowns, season-off and long-stay deals recalculated by real price, unit price and time left — using a Supreme Court ruling and an FTC/consumer-agency survey as the yardstick.

Cost Detective한국어

AFFORDABILITY BOTTLENECK

When a displayed discount hides the real recent low, shoppers cannot tell a good price — the block is price information, not the price.

Bottleneck examined: Information · Price

What a price bottleneck is · Who made this price — a case is labelled only with evidence.

How to read this

Calculators use only the prices you enter. Case figures are copied from the judgment and FTC release; a seller’s cost, margin or who funds a discount is not public and is not estimated. Legality is for agencies and courts.

01 / REAL DISCOUNT

Advertised vs real discount

Advertised discount
50.2%
Real discount vs 20-day low
16.8%
Gap
33.4 pts
Displayed price above the 20-day low
67% higher

You actually save ₩3,000 (label says ₩15,000).

"Lowest in ~20 days" is the reference the Supreme Court used (case below). Check price alerts, cart history or past orders.

02 / BUNDLES

Is the 1+1 actually cheaper?

Per unit
₩6,450
Same 2 units at the low
₩12,000
Real saving
None

This bundle is not cheaper than buying 2 units at the recent low — the same arithmetic the Supreme Court used for "no economic benefit".

Whether an ad breaks the law also depends on facts like how long a price applied; agencies and courts decide that. This is a wallet-level comparison.

03 / UNIT PRICE

Per 100 g / 100 mL

Single
2+1 pack
Bulk
Cheapest · 2+1 pack
₩441 / 100g · ₩1,987 / unit
Single
₩596 / 100g · ₩2,980 / unit

Multipacks sometimes use a smaller size per unit (500 g → 450 g in the example). Compare per 100 g/mL, not per piece.

04 / AMOUNT EATEN

Is the big pack really cheaper? Compare by what you eat

Option 1
Option 2
Option 3

Cheapest way to eat 150g under these conditions

Small pack · ₩1,900

Bulk / group buy has the lowest shelf price per 100 g, but once leftovers and extra costs count, Small pack is cheaper.

Small pack
Total ₩1,900 · ₩1,267 per 100 g eaten · shelf ₩1,267/100 g
Medium pack
Total ₩3,200 · ₩2,133 per 100 g eaten · shelf ₩1,067/100 g · 150g thrown away
Bulk / group buy
Total ₩4,900 · ₩3,267 per 100 g eaten · shelf ₩817/100 g · 450g thrown away

Packs smaller than what you need are bought several times. Delivery/travel cost and time are added once per source used. "Eaten later" only applies within the labelled use-by date and storage instructions, including how long an opened pack keeps. The calculator uses only what you enter and stores none of it.

05 / MARKDOWNS

A markdown only counts if you eat it

At the till
₩6,000
Effective price for what you eat
₩10,000
Effective saving
16.7%
Break-even
Eat at least 50% to come out ahead

For the seller a markdown avoids disposal cost; what you pay with is the time left.

06 / LONG STAYS

Weekly rate vs nightly × 7

Nightly × nights + fees
₩810,000
Long-stay total incl. fees
₩730,000
Real saving
9.9%
Effective per night
₩104,286

For the host a long-stay discount buys fewer empty nights and cleanings. Check whether cancellation terms are stricter.

07 / CASE

The Supreme Court on "1+1": tissue 1+1 at ₩12,900, 20-day low ₩1,780

Unless the ad explains otherwise, the "previous price" is the lowest price actually charged in roughly the 20 days before the ad (absent special circumstances such as that low price lasting very briefly or selling negligible volume). If a 1+1 price is at least twice that low, consumers gain no economic benefit compared with before the ad.

Item1+1 ad priceDay before20-day lowCourt
아비노 스킨릴리프 모이스춰라이징 로션₩19,000₩19,000₩10,450 (×2 = ₩20,900)Not a violation
아비노 크리미 모이스춰라이징 오일₩19,000₩19,000₩9,500 (×2 = ₩19,000)Likely false/exaggerated
애경 2080 진지발리스 K/나인모션 칫솔 4입₩9,900₩9,900₩4,450 (×2 = ₩8,900)Likely false/exaggerated
PB안주 8종₩7,980₩7,980₩5,580 (×2 = ₩11,160)Not a violation
해찬들 고기전용 쌈장 등₩5,200₩5,200₩2,600 (×2 = ₩5,200)Likely false/exaggerated
헬로3겹 천연펄프 화장지₩12,900₩12,900₩1,780 (×2 = ₩3,560)Likely false/exaggerated
LG생활건강 테크액체 용기 일반/드럼₩16,500₩9,600₩9,600 (×2 = ₩19,200)Not a violation
모나리자 벨라지오 미용티슈₩6,980₩6,980₩1,600 (×2 = ₩3,200)Likely false/exaggerated
훈제오리 슬라이스₩13,800₩14,800₩8,000 (×2 = ₩16,000)Not a violation
크라운 딸기파이₩2,880₩2,880₩1,440 (×2 = ₩2,880)Likely false/exaggerated
애경 케라시스 살롱 샴푸 외 3종₩13,500₩13,500₩9,600 (×2 = ₩19,200)Not a violation
CJ 햇반 발아현미밥/흑미밥₩5,300₩5,300₩2,980 (×2 = ₩5,960)Not a violation
대상 청정원 초고추장₩6,000₩6,000₩4,200 (×2 = ₩8,400)Not a violation
해표 압착 카놀라유₩6,300₩6,300₩3,150 (×2 = ₩6,300)Likely false/exaggerated
샘표 백년동안 흑초 석류/블루베리₩16,500₩16,500₩9,600 (×2 = ₩19,200)Not a violation
CJ 제일제면소 소면/중면₩3,200₩2,000₩2,000 (×2 = ₩4,000)Not a violation

"Was → now" ads, 5 items

ItemAdvertised "was"20-day low
해찬들 태양초 고추장₩21,700₩14,900
개별스위치 멀티코드 3구₩14,200₩6,000
마리끌레르 파빌론 차렵이불₩89,900₩71,900
스위트 믹스넛₩8,280₩5,800
옥시 파워크린 토탈케어 세탁세제 일반/드럼₩19,800₩16,400

The Supreme Court found the 7 flagged 1+1 items and the 5 "was" prices likely false or exaggerated. The corrective order and warning stood; the fine stayed cancelled because other ads it was calculated on were not violations.

Flyer ads, Oct 2014 – Apr 2015 · Prices exactly as in tables 1–2 of the judgment. Fed into the 1+1 checker above, all 16 items match the court.

08 / ONLINE MALLS

About 1 in 8 online gift sets raised the list price during the sale

800 New Year gift sets (Coupang, Naver, G Market, 11st)
12.8% (102) raised the list price during the sale, inflating the discount; 2% at least doubled it.
535 time-limited deals
20.2% (108) cost the same or less after the deal ended; 7 days later 12% (64) were still at the deal price and 1.5% (8) were cheaper.
FTC recommendations
Show what the "list price" is based on and how it was set · Separate unconditional discounts from conditional ones (coupons, cards, membership) · Make coupon conditions clear · Stronger monitoring by platforms

A countdown timer is not evidence until you see the price after it ends.

09 / WHY DISCOUNT

Why sellers discount, and what you give up

Near expiry / closing time
Unsold stock becomes waste with a disposal cost; any price above zero beats that. Your cost: If you cannot finish it before it expires, the discount shrinks.
Empty seats or rooms (matinee, off-season, long stays)
Running a screening or a room costs about the same whether it is full or not, so filling it cheaply is extra income. Your cost: You give up your preferred time or date; cancellation terms can be stricter.
Season-off / stock clearance
Turning stock into cash avoids storage cost and the risk of going out of fashion. Your cost: Fewer sizes and colours; exchanges may be limited.
Customer acquisition / bundles (1+1, 2+1)
Moves more volume per visit or pulls customers from a rival brand. Your cost: You may buy more than you need; the unit price can even be higher than a single item.

General economics. Why a specific seller discounts, and who funds it (maker, retailer, marketplace seller), is unknown without the contracts.

RELATED

Whether the pre-sale price itself is fair against cost: Cost Detective; prices inflated by a fad: Hype Detective; items pricier in Korea: Hogu Index; which supply-chain stage funded a discount: Distribution Detective.