Mate, you are welcome.
I was told all that about 6 yrs ago in the US when the company I was working for was thinking of getting an old cheap small jet instead of a larger turboprop than what we had at the time.
The initial purchase cost of the jet airframe was a lot cheaper but it was then ongoing operating and maint costs that were the problem.
The RVSM issue though was totally insurmountable as some older jet aircraft would have needed hundreds of thousands of dollars to equip them and get them certified.
So they bought a very nice, well equipped fast turboprop instead to operate easily below Fl290.