Racingjunk Forums - Helping my friend with motors

Hello. I am new to this as I came across it on a google search because I am helping my friend sell his motors. I will probably create a business account once I do more research. My friend is great at what he does but doesn't use the internet so thats why I am here. He builds motors for the local speedway and has about 10+ motors racing. He started out by doing one and then it preformed well and then he started to get asked by lots other to build their motors. So, he did a great job and the racers still have their motors so he has about $25,000 worth of motors he wants to sell because his racers motors are all holding up great. We are going to get a page of testimonials etc. pictures. Is this a good place to sell and how long do they sit on the market around here? Any info would be appreciated. Thanks.