Geo Prizm with broken timing belt!

I have a well cared for 1994 Geo Prizm with 94K miles. 60 days ago I was driving and my car suddenly seized up and stopped. After inspection, my mechanic replaced the alternator and battery. Since then there have been no problems. Yesterday, while idling, my car suddenly just quit. I was able to drive 1/2 block to get out of the way of traffic. The car had almost no power and was driving in a very slow but****** way. The check engine light, the battery light as well as the oil light came on. The car would start, but the moment I took my foot off the gas, it would die again. In addition, no matter how far I pushed the gas, the rpm's would not go above 1200.

I have taken it back to my mechanic who said that the timing belt had broken. He suggested also to replace my water pump since "it's likely to go soon", as well as 3 "exterior" belts that are cracked. This is going to be a $1000 repair. I'm wondering if this all makes sense?

Any information would be greatly appreciated.

Thank you,
Brandee