Yes, it's the Ultimate Affiliate script from groundbreak.com It's pretty good - a fairly simple install, and works solidly. We had some issues getting the cron job to run right but that was more from our end.
FYI, yes to the design client too. The site never used the script, so as there was a licence lying around unused we used it on our own site instead.
The cost when we purchased it was $200. It's not cheap but probably better than anything else within $1000. The advantages are you're not paying a 3rd party a piece of the pie which means more back for the affiliate. The script itself could use some TLC to look at, but the coding appears very sound.
Updates are fairly regular as things come to light.