About 15 years ago I had to replace our 16' garage door. I started to price out doors and then called a small garage door installer. To install and get a better quality door I had them install it for about a couple hundred more then what I would have to pay for just the door. Was well worth the extra cost. It might be something to check out.
I had the same issue with replacing an opener. After 15 years it sounded like a coffee can full of rocks rolling down a hill. Went to Home Depot, priced out their best model, etc. Then called the garage door place I deal with and they installed their best grade of heavy duty opener for only $110.00 more than I would have paid for the Home Depot model with self installation. After watching the guy install it, I was glad I did. Not that difficult, but extremely clumsy to do alone.
Home Depot would have gladly installed the model I was going to buy. (They simply contract the install out to bargain basement installers, and pocket the difference). But the whole thing would have cost more than what I paid the pro to install the better model with a better guarantee. Sometimes you'll find doing it yourself doesn't save what you think it might.