Do your research and watch for deals or used bikes. If you are comfortable working on or learning to work on bikes you can buy online otherwise the support from

Do your research and watch for deals or used bikes. If you are comfortable working on or learning to work on bikes you can buy online otherwise the support from a local shop will be worth more then what you save. mtbr.com is great for reviews and has a deals forum and page. bikeradar, pinkbike and some other sites that will crop up in google are great for reviews too. For reference I bought a new bmc trailfox tf02 with slx components for 1400 a few years ago and a friend bought a well used but well maintained specialized enduro for 900 last year...i'd say these prices are about as cheap as you should expect to find a good full suspension bike though hardtails can be had cheaper. There are tons of cheap but not great bikes out there. A good rule of thumb is to not get anything that doesn't have disk brakes and ideally you want something with Shimano hydraulic disk brakes as they are great and easy to maintain. Cheap full suspension is to be approached with extreme caution as it will be heavy and bouncy when you try to pedal it.