Here is a bump to kickstart some replies for you....
I have no idea what the price of popunders go for but I can show you some BETA results from split tests im doing with over 50 different popunder/popover/sales exit tools etc.....might interest you.
Best results from these 4 from 50 so far.
1.
ExitSalesman.com (Activates On Closing)
2.
SalesExit.com ( just sample agent not fully programmed in this example)...activates when you move mouse up the page and other different trigger methods
3.
ExitPredictorPro.com ( activates like number 2 via mouse or other methods)
4.
ChatPopBox.com ....With Facebook now getting more page views than Google this facebook style popup is very familiar,acceptable and comfortable to most surfers due to the fact they see and use it every day.....**(Available Now - See Sig)
Let me know if you want more details of the full range of products..thanks