Lav, we've come across some rusty gems at yard sales and scrubbed them to death, too.  Even with a little rust still on them, we go ahead and season them.  And season them again.  And yet again!  After a while the rust is either burned off or hidden under all that blackness and we just keep using the stuff. 
My husband cooks with cast iron pretty much exclusively.  Food is just better in it, I find.  I do however have troubles with just wiping it clean; sometimes crap is just charred right to the pan and a paper towel isn't going to cut it.  Best find ever was a plastic scraper from Pampered Chef.  It's the handiest damned thing I have in my kitchen (besides my husband, who does 95% of the cooking, lol!).  An even cheaper version is a bondo scraper from any local auto parts place.  They are worth their weight in gold (says the one who does none of the cooking and all of the cleaning up afterwards).

Scrapers -

  Sweet SPF 75, this is a bucket of deep-fried wack with crackslaw and mashed WTF  ~ Heather the Fug Girl       
  just words...