I have spotty skin + a lot of blemishes, red marks, dark circles etc?

i need a really good foundation with maximum coverage (ALOT) but i have olive skinand i can never find a good foundation. i need a foundation for about �0-�10 maximum as i have no other money + i have tried dream matte mousse, cool matte mousse, liquid satin, loads of foundations + i noe of them cover up my skin + either make me look pale or orange. not olive, help!