I was in a similar position as you when trying to decide if it was worth it. After I took a cabinet class at Woodcraft that was done entirely with Festool, it made my decision easier (still use the cabinet I made). Maybe this is something you can do if a Woodcraft is nearby and has a similar class. When I bought my TS55, I purchased the second 55" rail. I have never had an issue with connecting the 2 rails together. I recently bought the Betterly connector ($99) and I like it better than using the level I was using, but both methods work. I did buy the 75" rail, because my dealer had a demo model on sale and was to good to pass up. Would the long rail be better probably, but storing it would be more of an issue.
I wasn't sure if I would ever use the LR32 setup, so the holy rail upgrade wasn't a thought. Knowing what I know now, I would make that upgrade. Eventually I did buy the LR32 with the short holy rail from a FOG member, and if I ever decide on getting a longer holy rail, I would by the 96".
As for the dust extraction. I originally used my ridgid shop vac and it worked. However since I had to turn it on manually, sometimes I wouldn't remember or I am just making 1 or 2 cuts so I don't need it. Eventually I did buy the CT26 and the fact the vac turns on when the saw is started up is so much nicer and more effective. The 10% savings would have been nice, would have probably paid for the clamps.
The investment was large, but one I don't regret. My shop is tiny and eventhough I do have a table saw that I use for certain things, being able to breakdown sheet goods by myself is a major benefit. Not having to spend as much time cleaning up is a bonus.
Good luck with what you decide and even though this is a Festool sponsered/run forum, I think the members here will give it to you straight.
Bryan