To me, wangsa maju to Mid Valley isn't that far. Either u can take LRT or even driving is not a problem. Probably u haven't know the route to Mid Valley yet? hahaa ... But just my opinion .... With your budget and if u wanna stay near Mid Valley, a bit hard lo ....
Perhaps you can consider those apartments in Kota Damansara Area? I never did any research on that area ....