Earlier in the year, I had the good fortune whilst at Aston Marina (Stone) to pick up a fuel filter for circa £12. This being half the price of the one the boat came with. THIS filter had been in use for 400 hours and on taking it off, everything seemed fine - the PREfilter, also being clean... I suspect I'm changing them too often but I'd rather do that than wait until the engine has a problem with diesel bug or whatever... knowing my luck, that would only present itself heading down stream on a river with a weir looming.
Anyway the point of this waffle is having 'googled' the filter, I managed to find this website that sells them https://www.inlinefilters.co.uk/ and they work out at less than half the price of the "proper ones".
Suffice to say, I bought 4 so are set up for next year now.