As Moke says - replace once a year - for the money - not worth messing around, fuel flow is more relevant
Again - placing the filter in an easy access place for visibility and ease, kills 2 birds - one you can see it - two - easier to get to rather than jacking the back of the car up and lying on your side and back and showing the neighbours your yoga moves
Personally - I prefer the up front to the carb approach. My reasoning - If you have a steel line fuel line, and there is moisture - you can catch the crud better up front as you will get sediment from the tank and the line. If you have it at the back - you can catch the crud from the tank - but not from the line.
I have done both approaches to this subject and found from experience - better up front
As for costing - you can buy a pack of 5 and 10 for reasonable prices - just a case of using your own initiative and not just install anything - but something half decent