You're just experiencing bad timing! I found the IVC of my Dreams listed one day at the right price on FB Marketplace, only problem was it is in Houston. I rented a U-Haul trailer and drove down to pick it up. At the beginning of Covid-19 I was worried about losing my job and listed it here and on FB Marketplace and sold it in one day.
Place alerts and check FB Marketplace, Craigslist, and our classifieds every day. Know what you are willing to pay and make a good offer first. Know what value a comp cart or off-road package adds and be prepared to bid strong out the gates. I lost out on several Large IVC's because I had to sit and think if $2,000 used was a good deal (yes it is). Know the difference between older models with expanded metal vs. newer models with rolled bar grates as some of the parts like the gasket are 100% easier to change on new models. Once it gets cold and people want to buy Christmas presents you will see more smokers for sale.
Hope that helps!