← All Professor's Peculiarity variants
Kill-a-Watt Professor's Peculiarity
Community price on backpack.tf: 12.0–15.0 keys, last changed 2020-12-10 (5.7y ago). The live quote above, 18.1 keys, is 51% higher and last moved 17h ago. They are different measures: the quote is what traders and bots are asking and bidding on the classifieds right now, and it moves for thousands of items every day; the community price is a suggestion accepted by vote, which changes only when someone argues it should. A quote well away from the vote is usually a price that is about to be re-argued. Community prices from backpack.tf, read under an hour ago.
Steam Market asking price: $55.00 — the lowest of one listing for the Kill-a-Watt effect when we looked on 2026-09-01 01:39 UTC (5d ago). This is what a seller is asking, not what anything sold for. Steam pays out in Steam wallet funds, not cash, and Valve takes roughly 15% at the till — so asking prices there run well above the 18 keys, 8.77 ref shown above, which comes from the keys-and-metal market on backpack.tf. The two are different markets and are never blended. Steam lists the item as “Unusual Professor's Peculiarity”, with no effect in the name — the effect comes from the individual listing.
Price history
Interactive chart. Press the left and right arrow keys to move along the series, Home or End to jump to either end, Escape to clear.
The key axis converts at today's rate. Prices are recorded in metal, so a line that is flat in keys followed the key rate rather than standing still.
| Observed (UTC) | Sell | Buy |
|---|---|---|
| 25 SEP 2025 · 03:29 UTC | 14.0 keys | 7.70 keys |
| 29 SEP 2025 · 00:29 UTC | 14.0 keys | 7.68 keys |
| 7 OCT 2025 · 16:19 UTC | 14.5 keys | 8.01 keys |
| 12 OCT 2025 · 18:28 UTC | 17.1 keys | 10.2 keys |
| 19 OCT 2025 · 22:46 UTC | 16.2 keys | 11.4 keys |
| 4 NOV 2025 · 06:02 UTC | 13.3 keys | 10.8 keys |
| 9 NOV 2025 · 22:27 UTC | 16.4 keys | 11.8 keys |
| 18 NOV 2025 · 22:31 UTC | 16.4 keys | 12.1 keys |
| 26 NOV 2025 · 04:47 UTC | 14.7 keys | 13.0 keys |
| 3 DEC 2025 · 20:48 UTC | 18.4 keys | 13.5 keys |
| 27 DEC 2025 · 01:05 UTC | 13.1 keys | 12.0 keys |
| 22 JAN 2026 · 15:43 UTC | 13.2 keys | 6.61 keys |
| 29 JAN 2026 · 03:43 UTC | 16.2 keys | 9.65 keys |
| 1 FEB 2026 · 23:43 UTC | 15.5 keys | 7.60 keys |
| 8 FEB 2026 · 22:42 UTC | 15.1 keys | 10.2 keys |
| 13 MAR 2026 · 00:08 UTC | 14.9 keys | 5.97 keys |
| 15 MAR 2026 · 22:07 UTC | 14.7 keys | 6.19 keys |
| 22 MAR 2026 · 22:06 UTC | 15.9 keys | 8.64 keys |
| 1 APR 2026 · 02:29 UTC | 16.2 keys | 9.10 keys |
| 11 APR 2026 · 02:29 UTC | 16.4 keys | 7.36 keys |
| 29 JUN 2026 · 03:14 UTC | 10.3 keys | 8.97 keys |
| 5 JUL 2026 · 17:11 UTC | 10.5 keys | 9.13 keys |
| 11 JUL 2026 · 22:44 UTC | 10.3 keys | 8.96 keys |
| 19 JUL 2026 · 22:44 UTC | 11.2 keys | 9.76 keys |
| 26 JUL 2026 · 20:44 UTC | 13.0 keys | 11.3 keys |
| 14 AUG 2026 · 09:12 UTC | 17.7 keys | 15.4 keys |
| 19 AUG 2026 · 22:09 UTC | 17.7 keys | 15.4 keys |
| 24 AUG 2026 · 10:08 UTC | 7.60 keys | 6.61 keys |
| 29 AUG 2026 · 12:09 UTC | 15.5 keys | 13.5 keys |
| 30 AUG 2026 · 00:09 UTC | 15.8 keys | 13.7 keys |
| 30 AUG 2026 · 12:08 UTC | 16.7 keys | 14.5 keys |
| 31 AUG 2026 · 00:08 UTC | 16.7 keys | 14.6 keys |
| 31 AUG 2026 · 12:09 UTC | 17.1 keys | 14.9 keys |
| 1 SEP 2026 · 00:08 UTC | 17.1 keys | 14.9 keys |
| 1 SEP 2026 · 12:08 UTC | 17.2 keys | 15.0 keys |
| 2 SEP 2026 · 12:08 UTC | 17.4 keys | 15.1 keys |
| 3 SEP 2026 · 00:08 UTC | 17.6 keys | 15.3 keys |
| 3 SEP 2026 · 14:08 UTC | 17.5 keys | 15.2 keys |
| 4 SEP 2026 · 14:08 UTC | 17.5 keys | 15.3 keys |
| 5 SEP 2026 · 04:08 UTC | 18.1 keys | 15.8 keys |
Price history in numbers
44 readings since 25 Sep 2025Over the last 30 days the Kill-a-Watt Professor's Peculiarity's sell price ranged from 7.60 keys to 18.1 keys and is up 2.7% after 15 moves. Over a year it ranged from 7.60 keys to 18.4 keys (up 29.4%). Today's 18.1 keys sits at the top of its range: the lowest we have recorded is 7.60 keys (24 Aug 2026) and the highest 18.4 keys (3 Dec 2025). The price has moved 42 times since we began recording it — about once every 8 days.
| Window | Low | High | Change | Moves | Readings |
|---|---|---|---|---|---|
| 30 days | 7.60 keys | 18.1 keys | +2.7% | 15 | 16 |
| 90 days | 7.60 keys | 18.1 keys | +76.1% | 21 | 22 |
| a year | 7.60 keys | 18.4 keys | +29.4% | 42 | 44 |
Details
| SKU | 384;5;u56 |
|---|---|
| Last price change | 2026-09-05 04:08 UTC |
| Key rate when recorded | 64.44 ref |
Same effect, other items
the effect across the catalogue| Item | Value | Updated |
|---|---|---|
| 1,111 keys | 10mo ago | |
| 1,100 keys | 10mo ago | |
| 1,100 keys | 10mo ago | |
| 750 keys | 10mo ago | |
| 383 keys | 11h ago | |
| 268 keys | 2d ago | |
| 256 keys | 10mo ago | |
| 248 keys | 19d ago | |
| 249 keys | 2d ago | |
| 239 keys | 1d ago |
Other effects on the Professor's Peculiarity
same item, different effect| Item | Value | Updated |
|---|---|---|
| 1,250 keys | 10mo ago | |
| 486 keys | 29d ago | |
| 361 keys | 10mo ago | |
| 298 keys | 2mo ago | |
| 283 keys | 6mo ago | |
| 275 keys | 18d ago | |
| 124 keys | 5h ago | |
| 121 keys | 7h ago | |
| 102 keys | 11h ago | |
| 100 keys | 9h ago |
Priced similarly
across the catalogue| Item | Value | Updated |
|---|---|---|
| 18.6 keys | 2d ago | |
 Strange Widowmaker | 18.5 keys | 5h ago |
| 18.4 keys | 5d ago | |
| 18.2 keys | 11d ago | |
| 18.5 keys | 7h ago | |
| 18.4 keys | 6d ago | |
| 18.9 keys | 11h ago | |
| 18.6 keys | 4d ago |