3M PPS was a revelation to me. I use a mini gun with series 1 170ml pots. It is tiny and gives great manoeuvrability for spraying inside machinery. It even works upside down if needed. Shopping carefully, I paid £15 for two outer cups/collars (you only need one), about £50 for a new box of 50 filter lids and collapsible liners, and £15 ish for an adapter. So at the small end, I was in the game for £80 plus the gun.
I use one liner per colour per session as they can be opened and refilled a number of times over. £1.50 a session on average which is a bargain compared to a half litre+ of enamel and all the aggro the PPS saves.
Of course the bigger 400ml or larger pots must cost more but I don't recognise your pricing.
And did I say how good this system is ? Clean up or swap back and forth between colours is soooo easy compared to washing out a big fixed pot. flip the gun upside down, let the air in so it drains back, unplug the liner and blow an eggcup full of thinner through to clean the gun (just squirt it straight into the PPS adapter) ready for the next colour. Unused enamel stores in the liner for a few days too if need be.
We don't all have the luxury of shopping in slow time to find the best bargains, but if you are in business and earning money, the convenience and ease of this kit makes it a no brainer
