Solo ads are arranged somewhat informally through email correspondence, a lot of it is based on the reputation of the mail list provider, all the databasea of some solo ad providers I had have gone dead.
I don't really like te look of this sales page, which is more commercial than the typical publishers offering solo ads, but might one pricing reference
http://www.angelosayson.com/soloads
To get good solo ads, check for reputation and track records because there are some solo ads sellers that are not reliable. to get a reliable one, go to http://bit.ly/soloadwhiz. They did not only sell solo ads, they follow up till you are satisfied. I have used them several time.
I would go with Warrior Forum to find someone.
I can also offer you a solo ad service if you are interested. If so, we can talk more about it.
It depends on your budget and niche. For good quality solo ads try Warrior forum and Directory of ezines.com for low cost and quality targeted solo ads.
