I've got three CT22's. One is for the house, replacing a "portable" shop vac we kept in the garage for about 8 years. My wife uttered the words "I love this vacuum." while using it when we were working on our kitchen remodel. That should tell you something there. One of my CT22's has a boom arm and Dust Deputy and lives near my bench but easily moves around as needed. The third lives under my miter saw.

At a minimum if I ever went back to a traditional shop vac (and I don't know why I would) I'd throw away any shop vac hose and buy a good hose, not the semi-flexible pipes they include. I briefly had a non-Antistatic Festool hose and it reminded me how nice the antistatic feature is.

The boom arm--to me if you want to sell someone on Festool, give them a sander and vac for a week and let them use it. The second week, add a boom arm. Bet they buy it all on the third. Sure you could make something. I bet by the time you engineer and reengineer the thing a few times to get the kinks worked out you won't save much.

Nice used CT22's seem to come up pretty regularly. I've bought 3 for $175-$250 excluding shipping and depending on accessories. The lowest one I bought online and when it arrived I felt wasn't as described and the $175 was a negotiated price reduction. I resold that one when I had the opportunity to do a 3-way deal that got me a nicer one for little cash. It was fully functional as intended, just not very pretty (and it was the one for the house so...) I really haven't read much about long-term issues with the CT series vacs and obviously don't have problem buying them myself. If you want to save money, buy a used one. Just keep in mind the cost of replacing the filters if needed (buy Hepa ones if you do) and buying a hose if one isn't included.