Everything will depend on your costs. I have never paid retail price for my paper, I buy on sale when the sales hit. (Sign up for newletters with suppliers who carry the papers you use, you can save big, I've saved as much as 50% off my dark papers.)
Other folks shop at places with higher regular prices than where I shop. Combine my savings there with the sales, and my costs for the same products are dramatically reduced.
If you use OEM inks, thats the most expensive ink. If you use re-fill carts, the entry cost is lower, about the same as a full set of inks for an Epson ink jet, so to me, not much difference then the full set of OEM... but CIS/Bulk ink has a significant start up, so in the beginning, your costs for ink must included that overhead... in the long run, when the CIS is absorbed, your cost for ink will be lower than that of the OEM or Re-fill cart user.
Here is a thread where this is talked about a bit more by many members. It may not fit your question entirely, but may give you alot of food for thought when thinking this out. =)
Are you making cost or profit?
Good luck to you.
Approx cost to print transfer 
