That's how I came into my 1450. Was set to go about 2 hours away to get a 1650 and the day before I was going, I messaged him to find out what time. He replied that it was already sold.
Yes, sucked, but in the end I bought this 1450 off Al (forum member) and I'm glad it worked that way.
FB Marketplace is good...but like anything else, has its drawbacks. I've learned to never take someone's word I've never met. Soooooo many people don't show up. Just like people selling that won't honor your word, there are many more buyers that break their's. I now give the original interested party a "heads up" and a week to look or buy. I also tell the second party that I'm giving the first one a week and then they have dibs.
Being spring, a lot of lawn equipment prices are going up. I'd imagine later in the summer, early fall, will see some better deals...