Szise here is my suggestion look at your proxy sites find your best performing ones. Once you have done that take your best 4-5 and start your SEO campaign on them. If all the other sites you own are over 1-2 months old I recommend forward all the traffic from them to your best ones for 1 week then sell off all the bad performers.
Take what you make and buy more .99 - 1.99 domains and then repeat the cycle this is a great way to get some well ranked sites and make sure you make your own network site with only your sites listed there. Also from the beginning ad a newsletter sign up on all your sites so you can build a user base.
Thanks for the advice, i was never interested for SEO, probably i should reconsider my strategy with the proxies.