If your ordering offline Makaveli is right, middies off of a dealer shouldn't cost much, but unless they grow, they most likely won't have a ready-made seed collection. I keep my seeds in an airproof test-tube type thing throughout the year until growing season, but I also usually purchase 10 high quality seeds online. Those usually run you between 40-65 US dollars, depending on the quality of the strain your buying, and they have failproof methods of shipping, so thats definately not a worry on your part. I usually just have a nice crop of middies, one good sensimilla from the 10 widow or Northern Lights x Big Bud seeds I buy [like 42.50$], then let the other 9 grow as they will in hopes of getting some polenated females for next years crop.

Happy growing.