Never replaced one before, but almost had to on a past convertible. With that said yes that price does seem very high. From a quick search on sites many on here use for parts tops range from around $700 under if I saw right in the quick search. So installing yourself could be under 1K. Now installation I have no idea, but guessing here should be around a few hundred dollars. Again guessing on all this from quick google searching.
If your top was slashed are you planning on going through insurance as I am sure they can help you out on cost and locations. Personally I would try not to go through insurance as rates will likely increase more than the replacement will cost you over 3 years, but just wanted to throw it out there.