Assuming it’s in good working order and the following is true (or tweak slightly if necessary)....be sure you are including lines such as….like-new condition, no leaks or problems whatsoever, well-cared for, cover is like-new, includes steps, seating for x number of people, etc.
Also, post decent photos of the tub showing the inside and outside; too many people post horrible photos, blurry, badly framed, etc. And, I've seen lots of photos in the past that show "too much" in the background or around the tub, that lead me to believe the people who were selling it were filthy, or hoarders with stock piles of old items near their hot tub or crap piled up against their house, etc. - seeing photos like that, I wouldn't even consider buying a tub from anyone like that, tells me the tub was likely neglected big-time. Oh, and if the tub is already empty, please don't do what I've seen also, that being shots of the inside filled up with leaves, dirt or standing water of about a foot that looks like sewer water - a big no no; hard to believe some don't spend the extra 10 minutes to at least clean the sucker out.
Finally, you may wish to check with a hot tub moving service and get an estimate to move your tub to anywhere within 20 miles or so, then if you feel the need, you could add that figure into your selling price and then list, "Delivery Included!." For some, that is the issue holding them back.
Good luck!
