3's tariffs are some of the cheapest in Italy (choose "Super3"), and anyway they are listed on this site as well as TIM, Vodafone and Wind ones. Just
click here.
Staying in Bologna you should have no problems with UMTS coverage. Of course you need to buy an UMTS phone and the ones sold by 3 are "sim-locked" and cannot be unlocked before 9 months, and then only at quite a high price.