I like the idea of spells that let you emulate whatever other spells you want, but they should have a modest XP cost attached if they're going to do that. If you just take away the XP cost, Wish just SO out-classes Shades that it's not even funny.
Limited Wish being 300 xp per cast is just fine by me. It's still a fantastic spell, if used sparingly. If Wish/RR/Miracle had 500 xp costs for the spell emulation effects, that'd be fine by me. Maybe Miracle shouldn't have an XP cost, but rather just be restricted a little by DM Fiat in the way that your deity isn't going to grant a miracle that goes against his own interests.