96 Grand am Timing Chain Problem

I have a 96 Grand am that would not start last friday. I had a mechanic look at it today and he says it is the timing chain. Is it worth it for me to replace it, is it a lot of work to do? How much time will it take to fix it? Please help me!

What size engine is it?

sorry it is a 4-cyl 2.4 L i think, if the 2.4 L doesn't sound right i know for sure its a 4 cyl

I can do it cheaper than taking it to a mechanic.