There is a gentleman on the S&W forum that had at last count (probably two years ago) 26,000 rounds of full-power .357 through his AirLite 340 Scandium J-frame.
Having owned one (two, actually), I can tell you that I put about 50 rounds of 357 Mag through mine in the course of about a year...and my wrist
still hurts (two years later).
Shoot it as long as your wrist and your ammo budget will allow.
Let's see, last time I bought some (at least two years ago), the Remington 125 gr SJHP was $13/20...and I'm sure it's gone up since then.
That would be $65/100, $650/1000, and 26,000 rounds would be...
$
16,900. Wow.
If perchance it's worn out at that point, contact S&W...they'll send you a shipping label, you can ship it back to them, and they'll repair or replace it free of charge.
Hope your medical insurance is as good as S&W's warrantee.