We are frequently called to repair what the low bidders hoped would be acceptable. While we can usually help to one degree or another, whole scale miracle working is a bit rare.
Let's go back to the car analogy.
If you buy a brand new low end Kia, you get what you paid for. Basic transportation that should get you here and there. It is not a ferrari. It is not a Lexus. It's not an Acura.
When you go furniture shopping, the high end leather couch is going to cost more than the micro fiber alternative. And, if you buy the micro fiber, I can't turn that into leather.
The lifetime warranty costs more than the 'till the check clears' warranty.
The point being that things cost what they cost for a reason.
You can drop a hat over comparable bids from the top 3 shops in Tulsa. We all understand what it takes to do it right and back it up.
When someone comes in 30% cheaper, there is a reason. And, it ain't because they're smarter. It's a matter of how many corners you'll allow them to cut and get away with.
Just a little basic common sense...