MHPs For Sale

It seems that the number of MHPs for sale is dropping significantly. Is this due to them being purchased by new owners? Is it due to Seller reluctance to pay a fee to list them for sale on this site? There used to be quite a selection available. Now it is a lot of left overs that may already be sold but were left on the system to build a Buyer’s list for a realtor. Any insight would be appreciated. Don’t have the funds available to exactly buy right now, but am always looking for more.