Community price on backpack.tf: 10.0–12.0 keys, last changed 2025-09-21 (11mo ago). The live quote above, 8.77 keys, is 12% lower and last moved 8h 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: $25.01 — the lowest of one listing for the Kill-a-Watt effect when we looked on 2026-09-04 01:39 UTC (2d 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 8 keys, 47.55 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 Plug-In Prospector”, with no effect in the name — the effect comes from the individual listing.
Price history
24 observations
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.
Kill-a-Watt Plug-In Prospector sell price, 2025-09-25 to 2026-09-05: 24 observations, from 12.4 keys to 8.77 keys.
Observed (UTC)
Sell
Buy
25 SEP 2025 · 03:29 UTC
12.4 keys
8.47 keys
30 SEP 2025 · 20:48 UTC
12.4 keys
8.45 keys
9 OCT 2025 · 08:31 UTC
11.8 keys
8.89 keys
19 OCT 2025 · 20:17 UTC
11.3 keys
8.45 keys
25 OCT 2025 · 16:38 UTC
10.7 keys
8.05 keys
10 NOV 2025 · 00:40 UTC
11.4 keys
8.52 keys
20 NOV 2025 · 02:40 UTC
10.5 keys
9.32 keys
25 NOV 2025 · 10:49 UTC
11.4 keys
10.1 keys
17 DEC 2025 · 02:46 UTC
11.3 keys
7.99 keys
25 DEC 2025 · 13:05 UTC
11.4 keys
8.25 keys
29 DEC 2025 · 16:48 UTC
10.9 keys
6.57 keys
3 JAN 2026 · 12:49 UTC
10.7 keys
7.21 keys
12 JAN 2026 · 07:35 UTC
9.86 keys
6.65 keys
18 JAN 2026 · 15:33 UTC
9.96 keys
6.73 keys
29 JAN 2026 · 01:44 UTC
9.86 keys
7.50 keys
5 FEB 2026 · 14:22 UTC
9.53 keys
6.44 keys
16 FEB 2026 · 08:39 UTC
9.37 keys
6.91 keys
22 FEB 2026 · 16:41 UTC
8.94 keys
7.03 keys
7 MAY 2026 · 00:31 UTC
9.98 keys
8.16 keys
22 JUN 2026 · 17:13 UTC
9.45 keys
8.12 keys
13 AUG 2026 · 07:10 UTC
7.90 keys
6.86 keys
27 AUG 2026 · 10:08 UTC
8.54 keys
7.43 keys
28 AUG 2026 · 07:13 UTC
8.54 keys
7.43 keys
5 SEP 2026 · 12:10 UTC
8.77 keys
7.62 keys
Price history in numbers
24 readings since 25 Sep 2025
Over the last 30 days the Kill-a-Watt Plug-In Prospector's sell price ranged from 7.90 keys to 8.77 keys and is up 10.9% after 3 moves. Over a year it ranged from 7.90 keys to 12.4 keys (down 29.3%). Today's 8.77 keys sits in the lower third of its range: the lowest we have recorded is 7.90 keys (13 Aug 2026) and the highest 12.4 keys (25 Sep 2025). The price has moved 23 times since we began recording it — about once every 15 days.