Mate i use the free variety of AVS's with great success.. especially with
SexyAvs - They offer $20 / free signup, i convert very well with them
Naked Pass - $20 per free join as well.. they are run by the same guys as SexyAVS.. great conversions here.. + some nice webmaster referrals
Sexkey is still good, currently 20$ / signup... but for how long im not sure
Freenetpass is ok.. but only 15$
best of luck with it
Nurgle