Experimental might be cheaper, but if I rent it out I'm a commercial business. I get VAT back and the fixed yearly costs are tax deductible from my personal income (at least where I come from, might be different in other countries). Of course when I fly, I have to bill myself as well for the hourly cost, but I can "rent" my own plane at a much greater discount then what I would charge for others. So in the end, I still think certified is cheaper, and better for the local flying economy here. I'd rather sponsor them instead of the government with taxes
They just throw it away anyway.
As for the DR400, I've done some reading on them and they seem like very nice planes. Everybody seems to love them. I've also seen there are many versions. From 110hp effective 2 seaters to 200hp beasts. The O-320 and O-360 can also be flown slow for greater economy when time to get there is not important. A 10% reduction in speed saves 20% fuel or so, resulting in similar economy as the O-235 at similar speeds. They don't reach the ATL 13 liters mogas/hour, but they are a much more capable plane. Can all DR400s use mogas?
Wood doesn't have corrosion, so no expensive SID program to keep corrosion in check (except for the bolts here and there). I suspect rotting can be an issue when not hangared properly. I would be terrified for passengers to misstep on the wing and damage the fabric though.
How does the maintenance of wood/fabric compare to metal?
What's the difference between a -140B and a -160? Both seem to have the same engine.