Just remember that mobile homes depreciate like a car, not appreciate like a house. And typically you can only pay cash (Some banks will lend). Be careful buying a mobile.
Although some areas are predominately mobile homes, if it is an area that is mostly "Stick built" homes then it may not be a wise investment. Also, if it is on acreage and there is value in the land, it adds to the plus.
But again, becareful investing your future retirement.
As it happens, we are in a small market where the demand for rentals typically outstrips supply (college community). I suspect your market situation may be much different as it appears you are located in a large DC suburb. We have not seen a huge reduction in rental price nor a significant jump in rental inventory here because of the above named influence. You are correct that the seller will certainly be influenced by the cost of capital, etc., but I personally have a seller who is contemplating seller financing simply to move units that lenders appear reluctant to make loans for unless the buyers have 20% down and are going to live in the units. FHA is not an option for this development for several reasons. In this scenario, it is not the buyers who cannot qualify, but the property.
Sellers, what is your feeling? How long have you been on the market? Are you in a position to seller finance with a 20% down payment? If so, what is your desired rate on a residential unit? What rate of return are you looking for? We are looking for input so we can best advise our seller.
Agents - If you have sellers availing themselves of this route, what ROR are they looking for? What terms are they offering?