Currently I submit to sixty, and every month or so I tweak things and usually add a few more.
Some submitters submit to way over a hundred, but I've seen plenty of advisory posts on GG&J suggesting that you can be just as effective with a regular submit list of 12-20 "established" link lists.
I've never paid for a partner account, but I would be more than happy to invest $50-$100 in a partner account at the right site.
