"I forgot to tell you that the shipping is free if you pay $5,000 for my tractor .
If you want to go on with this deal , mail me asap because I have another
interested buyer and I need to sell this tractor fast."

Like, he'd want YOU to have first dibs because you mean so much to him no doubt. The guys is fairly good with English, but it is NOT his first language (and before anyone gets huffy about that statement, there are many scams originating in SE Asia).

"I forgot to tell you that the shipping is free if you pay $5,000 for my tractor ."

Shipping costs from San Jose to you would be in the thousands. It would take a flatbed and two drivers and a shitload of gas. That is one friggin' beautiful sales thing and he "forgot to tell you that the shipping is free."