P4 Golden. Bought the Vita Golden Edition, Physical Vita Cart and picked up digital on sale down the road. No regrets, one of my favorite games of all times.
Edit: Of course I have PS2 version as well, but somehow P4G on Vita just clicked.
Spent $80 on Phantasy Star IV in 1995 at Electronics Boutique (equivalent to $161.02 today). It was an expanded memory cartridge, which makes sense as it was originally being developed as a Sega CD game. I would have spent $100 and still felt good, spent well over 100 hours beating it 3x. Probably my favorite game on Genesis along with Contra Hard Corps and Streets of Rage 2 and Shining Force 1.