Unlike WDW, DLR's dining plan is not worth it because:
a) It doesn't save you any money; the best you can do is break even.
b) You do not get a set amount of meals, you get a set amount of $5 ("snack") and $15 vouchers and when you use those vouchers you don't get change. So for example if you want to pay for something that costs $4.95 with a $5 voucher, you will lose 5 cents. That's not a big deal, but if you have run out of $5 vouchers, you need to either pay in cash (which defeats the purpose of a dining plan) or pay with a $15 voucher and lose $10.05 (which can add up significantly). Disney also prices the dining plan so that you pay exactly for the amount of voucher $ that you get. So by buying that thing for $4.95, you are already losing money. You would have to buy things that cost exactly $5 or exactly $15 in order to stay even. Or you can buy things that cost more and you can break even, but you would have to be paying out of pocket.
c) You can't use the vouchers at Downtown Disney restaurants, which is where a large variety of the DLR restaurants are.
Instead, if you still want to prepay for meals, the recommendation is to put money on Disney gift cards. That way, you know you won't be losing money. You can use them at certain places at DTD and snack carts too, so you'll have a wider variety to choose from also.