I have 3-4 packages of the ones from the office supply stores, and they do leave that ring and aren't very good. It really turned me off of inkjet transfers. I saw some the other day in the craft store that looked pretty good though, so I might try again. The difference between an iron and a press is immense. But I bought a cheap press off of eBay and regretted it, then I actually bought a not much more expensive press from sunie.com ($249 -$269 I think?). For the small volume I do, it works very well. Eventually I want the $1500 slide out MaxxPress...

You can start small, but by small I actually mean at least a $500 investment. That got me my cutter, software, some vinyl, shirts, and I used my iron for about a month. Then I spent more to get a press.
I troll the local discount stores for blanks, and have found cases of blank shirts that I've bought in bulk at Goodwill. You're a poor college student, that's good... If you ever want to get bigger, remember where you are now and buy smart; that way if you aren't successful you aren't in debt.
Good luck, and do your homework! (In school and in t-shirt making.)