I just sold some leftover vouchers on eBay and they went for $90.01 for 5 (which is the going price often on eBay). I charged actual shipping of signature priority $5.75, for a total of $95.76.
5 bought through this place would be $16.50 plus $5.36 tax, plus $8.50 s/h, so the total for five is $96.36, .60 more. I don't think that eBay prices are way too over the top, since they compare to this place (and sometimes they go for less on eBay), if you are only getting 5 or so vouchers. If you are getting a lot more, then the shipping would be lower (but not the tax). But if you had a lot, and you used them at other than Beaches and Peppermarket, you would be hard pressed to get your money's worth.
I can't imagine if a group bought them together and then still had to ship them (and I would never just ship them first class), that moneywise, it would be worth it.
In the past, before DDE, I thought they were a great deal at $11 or so and if used at Beaches or Peppermarket. We even did ok in the parks, and did pretty good at POR when we shared a pizza, got the cheese and fruit as a side and the big orange juice (which they didn't have last time) and the apple pie ala mode. Then I realized that we prefer water (tap is fine) and desserts were doing us in. Now, even though I can't use DDE at the counter places in the parks, for us it's less to just buy our food without vouchers...although we still have some for the above mentioned places.