So, it appears that some tier 3 reputation projects not only have different requirements (annoying as I bought in bulk for the other ones!) but they also take 2 days to run unlike the tier 1 and 2 which were just 1 day.
They still only give 2k and 800 rep!
So, 2,800 rep every two days. 16k rep so far, tier 5 unlocks at 100k rep........84k rep to go......30 sets of projects.......so 60 days - plus the days for the upgrade between tiers during which you can't run rep projects.
Looks like there is a long life in this system!
I like the idea of the system, but some of the executions of it need a little tweaking.