Lots and lots....my rear windows installation was $500 for parts and labor, and that was just the window. So the whole top is gonna be well over $1000, maybe even over $1500. Good luck man. You can find the parts for it over at www.50resto.com the parts are not much but the installation is a lot.
Look through the phone book and call all the places in your area. Most ranged from like $1200-1500. ONe day this guy left a card on my car. I called him up and said he would do it for $800. I havent had the money yet, but im there as soon as i get the money. So look around.
Is convertible top installation all that difficult to learn? I mean, it's a formed piece of fabric! I'd imagine all you would have to understand is where and how it attaches.
In my own experience, i took it to a guy who worked at his own house, a "Bubba" if you will. I did this because after calling all of the businesses in Jacksonville, he seemed to be the most knowledgeable. It turned out great, he knew a lot and his price was unbelievable. I got a brand new glass window installed and everything for $320. Then he told my friend who will need a new convertible top soon that would order and install one for him for $650 total. Now that is just unbelievable and the guy wasn't shady or nothing. Sometimes it pays off to take it to a cheaper location, because quality doesn't always go down with it. I saved over $150 on my glass window by letting him install, and i am never going to a convertible top dealer again. But that is my own experience, good luck with you.
I can also assure you that this post is not , i am trying to help you guys out a little.
Some guys/shops can and do installations cheaper just due to the fact that they have all the experience, and can do the job quickly and correctly. It pays to do some shopping around first.
Normally, in my area, a T-lok and gear install would run no less than $550, but because I shopped around and found a place that does nothing but rear ends, the guy charged me $200.
Same goes for the TransGo shift kit - $150-200 anyplace else. Tranny only shop - $60!
I have heard Horror Stories from people that have tried to take the job of replacing the top themselves.
My advice? Leave it to the Pros!
One more reason is that you can't warranty your own work!