Consider
Grading Team Rocket's Mewtwo ex (Destined Rivals) is a marginal call rather than an obvious one. Raw copies trade around $347.42 while PSA 10s sell for about $540.91, a 24% Return on Grading. Worth revisiting if the raw price dips or PSA 10 demand picks up.
Most grading maths asks you to guess your odds of a PSA 10 first. This works backwards from the prices instead and tells you what those odds would have to be.
The number is different on every card. It's how confident you'd need to be that this copy gems before grading pays for itself, so 20% means roughly a 1 in 5 shot and 50% means a coin flip.
Grade it if you rate your copy better than that, leave it raw if you don't.
It assumes a 9 is the worst you'll get. Centering and edge whitening send plenty of modern cards back at 8 or lower, and that's not priced in here, so treat this as the floor of the bar rather than the whole of it. Selling fees aren't counted either.
(cost - PSA 9) ÷ (PSA 10 - PSA 9)
This barely needs
a shot at a PSA 10 (0%) for this to pay off.
The PSA 9 price on its own almost covers what you'd spend, so you're paying very little for the chance at a 10 worth $103.49.
Among the 93 cards in Destined Rivals with PSA 10 sale data, Team Rocket's Mewtwo ex ranks 17th for Return on Grading and 1st by PSA 10 price. Of the 11 Special Illustration Rare cards with PSA 10 sales, it is 4th for Return on Grading. The median PSA 10 in this set sells for $57.91. 4 of the 93 clear a 100% Return on Grading.
