The heavy lifting in sanding is at the low grits. If done correctly, much like honing, moving up in grits should go quickly. So, micro mesh and high grit papers over 1k should last a long time.
Where you will wear them out is, using too high a grit to begin with. I like starting with 600 grit, 600 scratches are easily removed with 800 or 1k for removing tarnish or just refreshing a blade.
If the blade is in good shape but polish does not make it pop, I use some 1k, and if after a few strokes it still looks dull, I drop to 600.
If you are doing repair work, removing scratches or pitting, you will have to go deeper with lower grits or greasless. Do remove any deep scratches with cross directional sanding before moving up, this will save your high grit papers.
So, a sheet or two of over 1k, will last a long time, but when I find them I always buy a few extra sheets. Castwell Plating carries a very good wet & dry selection, up to 3K for about .50 a sheet. Really after 1 or 2k you can easily go to a good metal polish, I use Mother’s for pre-polish, then Maas, Flitz or Novus for final polish, or buffer.
As Geezer said, do wash your paper prior to use and it can be unclogged with Bartender’s Keeper and Scotch Brite or fingernail brush to extend life.