There’s always a range of prices for psa graded cards and no such thing as a standard price in my opinion. eBay sold listings is your best research place and if you do want to find a decent purchase price just get the highest price and the lowest price and look for one near the lower range. Good luck
sounds fair seeing that a raw mint holo one costs around £14 here in the uk with grading fees of £9 that would bring you to £23 plus they don’t usually grade a 9 with these evolutions holo. The reverse is the same case but a raw one costs maybe £10?