No, right now you can get them for about a buck a disc, but that's still infinitely more expensive than my 75 single layer dvds for free after rebate! Just stick with single layers for now. It's faster to burn two full single layers than to burn one dual and it's cheaper. It's good that you got a dual layer because when Blue Ray and HD DVD get put in more pcs the prices of DL will go down.
I got my 75 on black friday but they're still relatively cheap without rebates.