Short answer: Expect prices to be equal with pop-top prices.
Long answer:
You can always call the manufacturer and get a quote. Even though Fiberine makes fantastic tops, they are not set up to sell to the public. They don't really want to. It's a pain for everyone (including them) when someone like me tries to order diretly from them. They don't even accept credit cards. They only accept cash or a check. In fact, they wouldn't even start building our top 'till they received our check and it cleared.
99.9% of their sales are to upfitter companies, and they want to keep it that way. It was a pain ordering my top from them. It'd be WAY easier to order a fiberine top from an upfitter rather than directly from Fiberine. I'm sure they can get you a list of companies that can install and sell their tops. In fact, they don't advertise prices because they're not wanting to distribute directly to the public.
Our installer asked that we didn't provide details like where we had it installed, how much it cost, etc. Price will really be determined by the top you get, the options you get, the level of trim you get it built out with, and the prices/quality of the upfitter.
For a ballpark number, I'd expect to pay $6000-10,000+ for various levels of "installed" from an upfitter. A lot depends on which model you get, whether you get features like windows, wood reinforcement, fantastic fans, solar panels, etc. and whether you want it upholstered, or left raw.
A lot of people assumed we'd spend maybe $2k total. It was WELL over that just for the top (and then we paid install later too). It's not a cheap upgrade, but for how we use the van, it's a very worthwhile upgrade.