Ahaha, so scrub that idea!! You'll get a MUCH less rediculous price if you hire when your out there.
Theres quite a few rental places dotted around, one i can recomend is in the quieter streets at the back of Kanya, can't rememebr what its called but if you head that way and ask people I'm sure they'll point you in the right direction. Think it's on the road d'Isidor Macabich (think!), and they have quads too if your still on that idea! There you'll be looking at no more than 50euros/day for a car, with discounts if you hire for longer.
Like I said though the excess will be a stinger, so for gods sake boy drive carefully!!