When I used to travel to remote Alaska Bush villages working for an Anchorage based company, I'd take my knifty Knitter looms with me to knit hats and scarves. The problem with storage space was taken care of with vacuum seal bags, or even the bags you seal with a vacuum sealer itself.
I get bags of yard at yard sales all the time for pennies on the dollar.
It's amazing how many relatives want you to make them a hat but, won't even bother paying for your thread or the shipping involved.
If you make them, sell them and don't tell the family unless you want to give it to them as a gift.
I pick up the Knifty Knitter looms for around a dollar a piece as well.. Stay away from the yarn hoiuses.. Even with the 40% off coupons you get for Michaels and stores like that, you'll find it a lot cheaper at Wal-Mart.
If you have to invest $7.00 for a skein of yarn for one hat, there's no way you'll make anything when you go to sell it.
Here's a great website that lists flea markets all over the place. I think they even have a book or catalog that you can subscribe to so it will be up to date.
http://www.work-for-rvers-and-campers.com/clarks-flea-market-guide.html