Jesus, have prices gone down that much? I remember when 1-80 (of which 68-80 is a large chunk of the EXP) was 100-150m from a legit service.
15m. I own iDungeon Pro, and can bot 16 hours a day. I don't know if the bot is working well nowadays, as it just went through a major overhaul due to some critical errors in it, but it would normally be getting 15-20k+ xp/hr.