Watch for end of season rummage/garage sales and any big local church fund raiser rummage sales, sometimes surprising stuff shows up at those. Plus with you looking for a bigger frame you'll stand a real good chance at getting the bike for the end of day 1/2 price sale, at least that's what I've seen here in Wisconsin and how I remember it when I used to live out west there. Keep looking, your bike will come along.

ps, here's a CL tip: do a word search in your local CL site at the top level, not within the bike section. I find bikes listed in with the garage sales, sporting goods, boats, barter, motorcycles, free, household goods, and just about in every other sub-section.