Cheapest RWD is the Nissan Frontier.
$18,990 and undercut the SMART by about $5000, Colorado comes in a close second $20,200.
Just saying the base SMART is about $200 less than a (full sized) Ford Transit.
As for FWD, I wonder if I could spec a Ram ProMaster (LWB and HRoof) upward of $70,000+ I can get the "build" towards $50,000 but then if I use my mobility requirements (public agency spec-ing a wheelchair conversion directly from FCA, that would add at least another $20-30K depending on what I want it to do.) Yeah, technically it would be outfitted by a third party but I would be purchasing it directly from FCA (FCA contracts out).
I also know that the Mercedes Sprinter is supposed to have a FWD layout coming in 2018, not sure though
Most of the luxury options are not likely FWD on their upper trim