Hey Barry,
I think you're doing a great job here with the site, with the exception of your commercial accounts area ideas. I'm thinking that you're asking for a little too much too fast here... with $10 for just two posts per month, and $18 for 4 posts/month. I'm thinking you could have just a flat rate of $5/month and you would build up your client base a lot easier and just set a limit of 4 or 5 posts a month. All those different options and prices you have suggested just seems too corporate or something to me.
Maybe there's a lot of people who will continue to post and join at your suggested rates, but maybe there'll be a big drop in the "little guy" businesses, or people just trying to start out in new ventures or with not much in the pocketbook by advertising here, and the WACCO communtity here could become more fragmented.
I think at $5/month, you keep your "doors" open to just about anyone and everyone who might be interested in being a part of this colorful community, which in turn would enrich the opportunities here more for the rest of us.
Just a thought...
Joe