Team Rocket's Weezing

If you're grading a copy, only do it if it's flawless—a PSA 10 is worth 6× a PSA 9 (£108 vs £17.94), but anything less won't justify the cost. Watch the condition of cheap listings: the lowest ask at £7.59 is flagged as LP, so a clean copy can command more. The market has been tight, swinging between £6.10 and £7.02 over the past month. PSA 10s move regularly—about 2 sales a week—but all 5 of the last sales went through as accepted offers rather than at asking price, so there's room to negotiate if you're buying or selling at grade.

• CautionA PSA 10 is worth 6× a 9 (£108 vs £17.94); only grade a flawless copy.
• CautionThe cheapest copy (£7.59) is flagged: graded LP by the classifier. A clean copy can ask more.
• NotableAt its 30-day low of £6.10 (the high was £7.02).
• NotablePSA 10 sells about 2 times a week (4 sales in 14 days).
• Notable5 of the last 5 PSA 10 sales were accepted offers, not asking price; leave room to negotiate.