Many are franchises, i.e. www.webuyuglyhouses.com, you will need to contact one of the franchisees that will offer you a decent deal. Keep in mind, they are out to purchase the home for under its appraised value, so you will not get what the home is worth, however it is most like better than BK.
In short, be careful, many are not scams and could benefit your situation; however you could deal with someone that does not have your best interest in mind. Always contact a real estate attorney in dealing in matters such as these.