We joke about it but as long as you have a coupon code and don't value your time, buying several extremely hyphened domains could be a nice little earner. You know, its likely once someone purchased them, they will let it drop instead of renewing... get the same domains again, and the cycle continues...
I still think they aren't worth the reg fee, but if there is a small market for them, and you know how to sell it... its all well, although not talking volume like 100,000 of them... I just don't think you could really do enough sales to make it a lifestyle business even if you lived in a country will lower living costs.
People claim to be able to sell them, but not exceeding 7 sales in an entire year makes it a risky venture IMO. Of course, you have other domains and perhaps a job along side, but the ratio isn't right for me. If you have a bigger margin (i.e. like non-hyphened sites) you can always cut your profit to sell a domain to turn the assets into cash... perhaps you got a big tax bill to pay, overheads or want to buy another better domain; with these, you could be left with them to expire. You wont ever get that time back from trying to sell them.
You cannot lose your cool... I think (for me) as soon as you get some surprising sales for a few of these, you will get over confident and burn up cash listing the rest on flippa... listing fees, commission and paypal fees later, you are making a loss...