[tguvot]

filters are cheap if you don't use fancy branded system that came up with it's own filter that incompatible with anything else

[an_aparallel]

You generally want to avoid cheap filters as they apparently can be tainted with formaldehyde

[tguvot]

standard, 2x10 filters from well known brands (pentek, apec or membranes from dow filmtec) are "cheap" compared to non-standard filters.