I think an important point to make is that Level IV does not mean better as opposed to Level III. There are Level IV plates that will stop armor-piercing rounds that will be perforated by M193.

As was mentioned above, you need to figure out what you’re most likely to be shot by and go from there. For me, the threat is much more likely to come from 5.56 and 7.62x39 threats which lands me in the Level III+ plate arena.

My current “soon-to-expire” plates are Safariland Rifle Threat III (model 2120) that stop all the stuff I’m most likely to be shot by (M193, M855, AK variants). They’re definitely heavier and more expensive than you want, but they stop the bullets that need stopping for me.

Save up and buy the good stuff or don’t bother.