Where to advertise my Gamekey Site?

[key4co.in]

Question is in the subject.
Advertising here isn't an option because it's way too expensive for me at my current state.
Is there a site where I can buy Ad-Space for max. 100$ per week?
The Site should be primarily focused on Bitcoin and other Coins since I don't accept any other payment and it should attract some people.
Are PTC sites an option to advertise?

Sincerly

[key4co.in]

anyone?

[E.exchanger]

there are many i suggest before posting a new thread how about searching google before. You can contact any of the mods here as the forum also rent ad spaces. good luck