not sure if its a scam
 

guy messages me about my item if its still for sale . I said yes and he asked if I would take a check and when it clears he will arrange pick up his name is mark Collins 1413 linda vista dr. ste d san marcos ca number 6265026397

Classic scam line. If he won't talk to you on the phone that is another bad sign. If he says he will send you extra money to cover having his shipping service pick up, he wants you to cash the check and pay ahead of time for a pick up that will never come. You will be out that money.