Among the most collectible forms of Rock N Roll is Rockabilly. Here are two to look for. In 1956 ,“Slip, Slip, Slippin In” by Lou Millet was issued by Republic Records. A copy is worth up to $2,000.00. In 1960 Rebel Records released “Dry Run” by Parker Cunningham. That 45 can get you $2,500.00 today.