I usually just shoot 200 rounds of fmj per shooting session and around 50 of my SD ammo.You definitely don't have to do it all the time. Just sometimes. Do it with the last mag as a finisher. And/or do 1-2 round training drills at the end of a string just to maintain proficiency. Think of it like sharpening a knife. The coarse grind is the cheap stuff. The fine edge is the actual SD ammo.
Or be like me (and very likely plenty of others on the forum) and just handload bullets of the same weight and relative velocity as your carry ammo on the cheap so you don't have to spend SD ammo prices on your training ammo for SD scenarios.
I’m going to buy some 124 grain fmj once I get through the 115 fmjs I have stockpiled, since I recently switched back to 124 grain hsts.
I’m looking into learning how to reload but it just seems so difficult and risky to me.