I'm not going to pretend to understand all of the details of how torrents actually work or the running of this site. However, there are a couple of things in your post that struck me.
Firstly, your idea sounds virtually the same as renting a seedbox, which can be done for significantly less than $1 per GB. I've been shopping around recently, and have seen deals for around £9 per month for a TB of storage and 10 Gb/s up/down speeds with no traffic limit. Granted, the speeds may vary, but it's still a good way of seeding properly and does wonders for your ratio.
Secondly, if this site was to actually offer (or require) you to rent server space off it then I suspect this might have detrimental effects. In general most torrent sites are only able to operate based on the fact that they don't host any copyrighted material. If they start renting out server space that you need to put your uploads into then even if hosted externally it might be argued that the site itself is, by proxy, hosting such material, which could open it up to enforceable legal action.
Hopefully more knowledgeable people will be able to weigh in on this.