domain name $10.00 per year
vbullletin $85.00 per year
I did a search on Google for "oscommerce" and didn't see your site in there. But then you admit you have not promoted. For under a hundred dollars someone could have a unpromoted forum just like yours.
Yeah, probably could - just find the 'right' domain name. Just because they all cost $10 to register doesn't mean they're all only worth $10. If you own webhosting.com I'll gladly give you more than $10 for it
I get 50-100 folks per day just because they went to their browser and typed in oscusers.com just to see if something was there.