Perhaps consider some sort of a media buy? It's absolute finger in the air without knowing what you do, but assuming your site is in a niche with bloggers/other

Perhaps consider some sort of a media buy? It's absolute finger in the air without knowing what you do, but assuming your site is in a niche with bloggers/other non-product related sites, ask some if you can put a banner up for a week to test. You're spending 105 a week now, you'd be surprised at how little some hobbyists will take (especially if they're seeing $x a day AdSense income).