Strong Buy
If you own a clean copy of Mimikyu-GX (Lost Thunder), this is a card to get graded. At $123.28 raw against $3400.00 for a PSA 10, that works out to 1494% ROG. Worth putting near the front of your next PSA submission.
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 (1%) 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 $3186.72.
Among the 87 cards in Lost Thunder with PSA 10 sale data, Mimikyu-GX ranks 3rd for Return on Grading and 4th by PSA 10 price. Of the 20 Rare Ultra cards with PSA 10 sales, it is 1st for Return on Grading. The median PSA 10 in this set sells for $237.50. 42 of the 87 clear a 100% Return on Grading.