timing belt

i have a 98 dodge avenger, 2 wheel drive, automatic, with an oil leak for about a year, thats gradually gotten worse, the check engine light and break light stays on constantly when checked nothing major shows up. Recently i had to replace several fuses that were blown including one major fuse that kept my car from strating. No "major" motor work done since i've owned it for 2 years now. 4 weeks ago i began to hear a little squeaking under the hood, familiar sound of a belt fixing to break. 1 week after that my car died on me in full drive 65 mph, up a hill and has not started since. A local mechanic said it was my timing belt, and this type of car possibly a valve was blown too. Timing belt alone is $450 but the only way to tell the vavle is bad is to fix the belt and see if the car runs, and if it doesnt i will need to repair the valve which will cost $1200 due to the major labor work of tearing my car down to get to the valve. is this true with this type of car and am i seriously dealing with this type of money? is there a cheaper way to deal with this? thanks