The Post ofice PB2 padded bags at 151 mm x 229 mm are a bit tight and only suitable for thin DVD cases,(3 months ago they cost

me 45 cents each when I bought a 100 of them).

The better option is to buy from an ebay-packaging seller on here who have theirs at a cheaper rate and their bags size is 172 mm

x 220 mm,(which means they have more room and will fit a standard DVD case easily).

If you sell 2 in one lot they also have 236 mm x 350 mm bags.

Other options are B1 and B2 boxes if you sell 5 or more to one buyer.