I don't think you can get that many IPs these days, as they've become quite scarce. Most datacenters require a valid technical reason why you would need them. In practice, the accepted valid reason, is to install an SSL certificate.
That being said, IXwebhosting offers some 15 IPs with their shared hosting. You could buy multiple accounts from them, until your needs are met. It would still be cheaper than buying the dedicated IPs separately, as they tend to be about $2/month.
On the other hand, based on my experience with IXwebhosting's shared hosting service, I can say that, at its best, it qualified as mediocre.