I do this on the side for fun. I can scan a pretty fast speed (around 40-45k IPs per minute) so I can cover a lot of ground. I tend to stay away from publicly scraped lists as they die extremely quick and are shit usually from what most people say. I stick to port scanning, either by ISP, or by range. As for numbers, on a good day I can probably scan around 7-10k online and working, and on a bad day, maybe 5k-ish. Although to be honest, I've never really compiled a huge master list of the ISP's and ranges. Also I try to steer clear of the L3's so I'll stop scanning those a lot of times if I notice that a certain ISP or range is yielding nothing but L3's. All in all though under optimal conditions on a good day if I compiled everything I think I could scan over 10k online and valid and if we through in all the L3's that number might crawl as high as 15k. If you're taking a similar approach and scanning your own fresh instead of leeching or scraping though, you'll have quite a few people interested in buying them. I've shared some of mine with a few friends for free just because I buy subscriptions for mine, but I've probably turned down a dozen people the last couple months requesting to buy them on a regular basis, mainly because I don't want to get tied down with it. I think you'd find quite a few people willing to buy them though.