Build a 904 or buy one off the shelf?

To be perfectly honest guys, I'm probably not going to rebuild a transmission myself before this Spring. Too many other projects and work...so my options are paying someone to build my 904 or buying one off the shelf.

I haven't settled on a motor yet...but while I want to put some power under the hood, Im not going prostreet..so most likely less than 500hp would do the job.

What is a typical 904 build going to run?

Would it be significantly cheaper than going with something like this?

http://www.tciauto.com/tc/streetfighter-transmission-67-later-318-340-360.html

Is there another vendor who might have a better product or a better price?

Thanks for any opinions and insights!
-Mike