My comments were more on the seller's cluelessness than anything else. I understand the need to protect yourself in a financial transaction but there are various ways to accomplish that and still be a smart seller. The seller in this case could have stated in the ad that he would accept cash only in which case I could have decided whether it was worth the hassle to me of getting the cash. If the seller had simply said to me he wasn't comfortable taking a check I would have offered to leave a check with him and arrange to get the mower later. In numerous other similar situations where the seller indicated they would accept cash only I have offered, and they accepted, to send them a check and give them a week to deposit/cash it before picking up the item--to me its a convenience issue as I rarely pay cash for anything and rarely have more than $20 in my pocket. There are a lot of people who can easily spend $100,000 on the impulse purchase of a sports car but would have trouble getting a candy bar from a vending machine that only takes coins or small bills. In my experience the guys who carry the most cash don't speak English and work for $8 an hour.
Tom is right that waving cash in someone's face is the best way to negotiate a cheap price but, for me, it's not worth my time to chisel $20 off of a $200 item if I think it is fairly priced. If I had $200 cash with me I would have offered this seller maximum of $150 and I'm confident he would have taken it so the way I see it he's out at least $50 playing the hard ass. Many times I have had past sellers give me first shot at new items they wanted to sell simply because they know I'm willing to pay a fair price and the deal will be hassle free. I don't want to do a deal where the seller isn't happy and if they have inflated expectations of the value of what they're selling I just pass on the deal. I know that for all the $20 bills I've left on the negotiating table I've made $200 or more on subsequent deals with the same sellers.
I don't have much use for sellers who believe they are doing me a favor since they are the ones who want (need) the money not me. When I want to sell something I go out of my way to make the deal easy for the buyer and usually get a good price as a result. For those of you who don't want to take a check from me, that's ok--we can still be friends even if I don't buy anything from you.