Honestly, I've never understood why wishes/tomes don't just increase inherent bonuses by +1 up to +5 total (it's not like there is an escalating price increase - 5 +1 tomes cost the same as 1 +5 tome). 5000xp a pop seems a really steep price to pay for not waiting a few levels until you can afford a full 5 wishes. Create 5 wish scrolls and wait to read them all at once = +5, Create 5 scrolls over time and read them as you get them = 20000XP flushed down the toilet. It just seems really stupid to me. You can increase the enchantment bonus on an item by later paying the difference, so I don't see the reason to treat inherent bonuses differently.