How do you get comps for a lot with 2 trailers on it in YUMA AZ?

[Emmanuel Soto]

I'm talking to a seller wanting to sell a 1800 sq ft lot with 2 trailers on it and owns it free and clear. He doesn't know how much it's worth and I want to know the most i can offer for it but not sure how much in a investor would pay to wholesale too.

Is a real estate agent the only person that can help me with comps and maybe a buyer? would it be worth it paying her a commission or is there another way?