The company I work for reckons a full issue for a staff uniform costs them c. $300 on average.
(that's a set of 6 shirts, a couple of pairs of pants, shoes/boots (some staff get regular, some staff get safety /shoesboots), waterproof coats for about half the staff, a cheap jacket for the rest. the whole lot logoed/stamped etc - all logos are sewn except on waterproof jackets (transfer) and shoes/boots (stamped, or little cloth tags sewn in during manufacture))
Of course that is a bulk purchase rate - they have about 100K uniformed staff.
When a new uniform style is introduced, it is now phased in to replace the previous issue, so for a while composite styles of uniform may be seen, and old stock is issued for a while after the changeover (what style you get depends on the popularity of that size!).
It used to be a complete re-issue in one go, but the company changed that policy about 7 or 8 years ago to save cash.

In the case of a phased re-issue, the extra cost is pretty much zero (over the existing uniform budget).

I guess the TSA costs would be somewhere in that ball park.

The number of "lost" scanners depends if there is a phase-in period or not.