First of all, be careful. You can get infractions for double posting and bumping a thread like that. Now, about avatars and sigs: Then general rule of thumb is you get about a penny per post for a sig link and half of that for an avatar per month. So with your 300 posts, you might be able to get $3/month for a sig link and $1.50/ month for your avatar. But this place is really strange. Sometimes you will get much less than that, sometimes you will get more. The only way to know is to try and sell it and see what happens.