Worth it? Galaxe 520mm for Canon 450D (1 Viewer)

I got the specs today for what connecting my 450 D to this (http://www.galuxe.com.tw/telescope_GS520_802.html) would give me: Equivalent Focal Length of 832mm/F8.4 (according to the guy in the shop). I would run me about $500 US or slightly less for the scope, adaptors, and a nice tripod, as he said he could bundle them and give me a discount (still waiting on the firm numbers).

That focal length is a little longer than I was expecting, and the f-stop seems a low, but I've never digiscoped. Does that seem par for the course?

The focal length of the scope is 520mm and you are arriving at 832mm by adding in the crop factor of the camera. The true focal lenght is still 520mm though. The camera just crops the image so that it looks like a photo taken with a 832mm lens. Don't know anything about the scope so you can only go by the few photos on the web taken with it.

Paul.