Hi Tanya, it looks like your post got cut off. This is because you typed it all in the title... You can add as much text as you want in the body of the post.
What is your question? I can fix it for you :)
I am going to take a stab at the answer on this without knowing the entire question. Bath Fitters is a franchise operation. They have a pretty good product for most homeowners who really do not want to go through all the expense and mess of tearing down their current bathroom just to make it look new again.
The reason why I said Franchise is because as with other posts that I have written on, I have said the Franchise is only as good as the person doing the work. While their product line is quite extensive and they do have some real nice products. If the person doing the work came from a background of finance and never touched a tool in their life, the results can end up being less then desirable. However if the person doing the work has had years of experience in the trades, even with poor quality materials can make the job look great.
As far as cost comparison. As a contractor, I can tell you nothing beats the tear out and proper replacement system. Although dirty, sometimes smelly, and in most cases a bit more expensive. You do have the option of tearing everything out and designing what you really want. With a bath fitting project as they sell, everything pretty much stays as is.
They can remove the fixtures and upgrade them as they can with the tub drain. But a tear out can not only change out the stuff, but can and often does expose issues that perhaps may become an issue in a short time. Allowing a repair to be performed long before you have to tear out all that new work when you could not see it.
So, if your looking for a reasonable upgrade, and do not want to go through a complete tear out. Their your guys/gals, But if you want a completely different look go the old fashion method and gut and rebuild.
Check their jobs out. Ask to contact several clients both recent and those a year or so old. They can offer you the best advice.
lastly check to see what their response to issues that perhaps come up during the repair. What type of cost overages should you expect?