I need help with a lock

A few days ago, my key snapped off in my lock. I tried everything to get it out short of ordering a key extractor (which would have taken a couple weeks to get where I am because I’m in a weird area) and spending $300 on a locksmith. A neighbor of mine offered to try to get it out. He decided to take out the lock in order to get the key out. Now I think I could get the lock put back together with the pins in the right place with a little time (I may be overconfident, but I’d like to try before I spend money on getting a new lock or having someone come out here to fix it). The issue I’m currently bumping up against is that I’m missing a part. The thing that caused the lock to be so hard to turn (which resulted in my key snapping) was a bent spring. I cannot get it back into shape, so I’d need to replace it. But obviously, it needs to be a specific size and length. Is there no way I can do this myself? Is there a way a locksmith could fix the lock without that part (like could he or she replace that part for me)? I still have a working key, and I have other locks in the house that use the same key.