Probably, unless you don't have those skills or the time to perfect them.
Bruce, I bought a FilterBOSS already, but won't install it until this summer as the engine's getting pulled and I'm entirely redoing my water tankage and distribution.
My rationale for buying it was based on several things:
1) is the obvious: it provides an impressive pair of filters that, if one is clogged, the other can be selected without stopping the engine.
2) This can come in handy in places where the diesel is not necessarily clean, or should water get into a tank. Keeping the fuel clean and water-free seems, according to the cruising narratives I've read, to cover 90-95% of the diesel trouble out there, with most of the rest falling under "spares" or "failure to do the basics".
3) The FilterBOSS comes with its own pump, providing not only a level of redundancy, but also a method of polishing one's own fuel should rough seas or a bad fuel-up introduce particulate matter or other containments into your supply.
4) I currently have two 50 gallon keel tanks. I am converting a former SS holding tank beneath the engine (of all places) to a 40 gallon daytank which will contain ONLY polished fuel from the FilterBOSS. The logic is that I could have really nasty stuff in the main tanks, but I'll have at least 24-36 hours of straight motoring range to find fuel.
Yes, you could build such a thing, and people do. But while I'm happy to use a flare tool and a compression fitting on my Atomic 4, I simply don't want to do this job going offshore, because it might fail due to my inexperience, and I cannot do such a neat and compact job.
I installed one 2 years ago and for ME it was worth it after daily filter clogging on my self delivery of my boat from Annapolis to RI. I have 2 - 70 gallon tanks and with the FB I can polish the fuel from P to S tanks, P to P, S to S, S to P. There is a warning buzzer if the current filter is becoming clogged and now I simply flip 2 levers and keep right on going. Andy Keenan the owner actually helped me with the schematic to accomplish the full flexibility I wanted. I originally tried doing it with copper pipe and it leaked like a sieve so I re-did it all with proper hose. The octopus of hoses under the stairs is needed for my flexibility of multi-functions but the basic unit in the closet below is really all you need for a basic installation.
I have 2 Racor 500 turbines. Both have vacuum gauges as T handle replacements. 2 years ago I plumbed in a $50 marine grade fuel pump (NAPA). I run it at the docks, but really like to run it when under sail so the fuel is getting bounced about. It doesn't have the flow rate etc. of a dedicated polisher, but it cost me under $100 for pump, fuel line, fittings, and wiring. Also the fuel pump is great for filling the Racor up after a drain/filter change.