consumables

Hi, Where should I be shopping for consumables such as air filters, oil filters Air con filters etc for the best deals?

Hi guys, Another off topic one, hoping the wide audience can help. I know of sites that are cheap fior most PC items, scan, ebuyer, crucial, etc. However I need more ink for my printer soon and find none of them are particularly discounting on OEM HP Cartridges! I need a C6578...