I spent most of the morning looking for oil filters. I generally buy filters for the GPW/CCKW in bulk (well, 6 of each at the same time) to save.
Sad truth is that the bulk filter places online have raised the significant savings to not the case qty, but the PALLET qty. Unless you are into the $2000+ range on an order there is no significant saving that isn't eaten up by the shipping cost.
Case in point, 12 WIX 57060 (for my caliber) 6 51503 (Senior filters) and 6 51100 (Junior filters) would save me $25 vs buying locally once shipping was applied. The local NAPA generally gives me the shop discount (10-15% off retail) if I pay cash. Previously there was either free shipping on case QTY, or the online prices were 40-50% of retail. Best discount I could get was 20% off unless I bought $120-$250 in a single filter, and STILL have to pay shipping
Bottom line... if you get a good price jump on them! And don't forget to share where you got them from.