Depends on the printing process, the brand of the shirt has little to do with the process, but the cotton content has everything to do with the type of process used to print your artwork.
This is not correct.....sublimation is done with a dye-sub paper and sublimation ink in either a Epson ink jet or Ricoh printers on high polyester content shirts (100% polyester works best), it does not work on 100% cotton shirts or dark shirts regardless of the cotton content.
This link might help you learn more about sublimation.
DyeSub.org - An educational site for dye sublimation and digital transfer printing.
True....but the waste cost in very minimal and figured into the cost of the design.
Hate to say it but "cheap" and "best" don't fit into the equation, for transfers printed on a ink jet or laser printer you will need the printer, correct ink, correct transfer paper, the shirt should have a high cotton content for this to work although it will work on 50/50 shirts.
You really need to read this thread to get a better handle on the different printing processes.
http://www.t-shirtforums.com/general-t-shirt-selling-discussion/t37985.html
Check out the two links I posted above, both will give you some insight and probably more questions.
Hope this helps.