Good to see official presence on the forums!
Yes, there are people who would buy (and have bought) commercial plugins for Blender. If you’re interested I would seek out Jonathan Williamson (Contours), the developer of bSurfaces (commecial before released as GPL), and the developers behind Thea. The Thea plugin has since been released under the GPL as well, but it would probably be useful to talk to them anyway to see what sales were like before they switched, as well as getting some potential pointers for how they got their plugin working. It is one of the only examples I’ve seen to date that is pure python while not violating the GPL license and retaining excellent speeds for export/buffer management.
Now, integration would have to be pretty good for people to consider buying. A simple exporter probably wouldn’t pass muster (and that’s not just a Blender thing). Indeed, many Blender users are hardcore Open Source fanatics, but those of us using Blender professionally know that with a good feature set and support, the price of a plugin will be paid for in a very short amount of time. And there are quite a few of us here using Blender professionally on a day-to-day basis.
Hopefully you guys will move forward with this, I’d love to give FurryBall a try, as I’ve heard some great things!