how much and where to have timing changed?

[irondiezl3]

I'm at 110k now. I baby my car Penz plat then ultra when it was introduced every3k. My questions is, I've seen so many threads say replace timing at 100k and my brother lost a car from not replacing timing. I dont really trust anyone but dealer for that im assuming ill get raped on price. whats a rough ballpark estimate for that job/ Does it matter what part I get or is it oem only? are there signs of timing going bad and will it drive different with a new one? thanks for advice.