I've had good luck the past year with the Cabela's pre-cut bags. I've used both the plain bag and the the zip top style. I've had some problems with the zip top tearing when trying to open/re-use it. Pricing was pretty good. Sure a lot easier than measuring/cutting bags off a roll.

http://www.cabelas.com/product/Cabelas-Vacuum-Sealer-Replacement-Bags/713888.uts?Ntk=AllProducts&searchPath=%2Fcatalog%2Fsearch.cmd%3Fform_state%3DsearchForm%26N%3D0%26fsch%3Dtrue%26Ntk%3DAllProducts%26Ntt%3Dvacuum%2Bseal%2Bbags%26WTz_l%3DHeader%253BSearch-All%2BProducts&Ntt=vacuum+seal+bags&WTz_l=Header%3BSearch-All+Products#BVRRWidgetID