I'd round it to probably just 2 significant digits.

I don't care if it's $91,132 or $90,725 or $91,412 - all of those are effectively the same as $91k (unless I'm the vendor trying to work out who's leaking my pricing).

What I'm looking for as a potential new customer is to see if it's going toi cost me ~200k or ~90k or ~10k or ~3k.

I would show an interval that's within 5% or whatever, but use the same intervals for all accounts otherwise people will be able to deduce the original number by calculating the midpoint :)

to the nearest thousand or hundred.

731 seats @ $77492.32 could be ~700-750 seats at ~$75k-$80k and that's still a useful guide for me.

A lot of estimations are done with "t-shirt sizes", and just knowing a rough range with a rough margin of error makes things so much easier. I'll let my procurement team fight for the $3k or 31 user difference, and do the back and forth with quotes, but I can run w/ those broad numbers right now