There are many popular villagers that end up getting voided now so it depends on luck.
The New Neighbor Network doesn't seem as active as it was at the start - I also think a lot of people opt to go Island hopping or campsite resets to get the villagers they want now, which I feel has decreased the value of the villagers considerably.
I agree with Cheezu! Most of the more popular villagers have been losing value as the majority of TBT'ers have gotten their dreamies. Mine are mostly C tier or below but I've found no real issues getting ahold of them.
It's still a safe bet to post tho! There are always new people coming in who want the iconic cuties. Just be persistent and flexible with price and you can usually get a decent deal.
Yeah like Weiss Schnee said, a lot of people who have been on the forum seem to have gotten their dreamies. If you really want to get a lot of value out of him, might be better off posting on Nookazon or some other trading websites
Ooo Discord is a great avenue to explore for trading and selling villagers. It's a bit more fast paced and on demand than a forum where sometimes hours go by without a reply.