I'll let you boys in on a little secret. If you start to check out 'antique malls' here in the midwest, you'll find a lot of used cast iron skillets - for not much money. Look 'em over carefully, you don't want one that's been used to melt lead for fishing sinkers. Assume they're in pretty good shape, but if you wipe your fingers in the pan and it comes out lead-grey, leave that one for a Raider fan.
You're all familiar w/Lodge cast iron, but there was another good cast iron making competitor in the olden days that made very good cast iron - the brand name was Griswold. If you find old Griswold skillets, you might just want to snatch 'em up, they're good stuff. My Dad used to compete in cast iron cookoff competitions in MO, OK, TX and he swore by Griswolds.
Another thing to keep an eye peeled for - square cast iron skillets. They're really for cornbread (despite what your math teacher said, pi are round, cornbread are square) I always put mine in the oven for 10-12 minutes w/a bit of butter before I add the cornbread batter. Love that batter-hits-the-hot-fat sizzle. Round skillets work fine, but the square one I inherited will always be a fave. The little 'corn sticks' molds are dandy too (watch 'em - the batter cooks up fast and you'll burn your cornbread if you follow advice/timing for a regular pan)
Pop was the cast iron king in the family, he had about 8 or 9 great big dutch ovens he used in said cookoff competitions. They got a good clean up at home - and he always stored the lid on the pan w/a peg of wood or a rolled up bit of paper towel under the lid, to let some air get in under the lid, keeps rust from forming was his explanation. I do it because he did it (and I suspect he did it that way because my grandmother did it that way.)
A man can never own too much red wine, too many books, or too much ammunition. -- R. Kipling