Strong Buy
Grading Volcarona #15 from Steam Siege currently looks like a clear win. Raw copies trade around $0.80 while PSA 10s sell for about $1500.00, a 1552% Return on Grading. The upside only holds if the copy grades a 10, so inspect edges and surface first.
Among the 34 cards in Steam Siege with PSA 10 sale data, Volcarona ranks 3rd for Return on Grading and 5th by PSA 10 price. The median PSA 10 in this set sells for $250.00. 22 of the 34 clear a 100% Return on Grading.
