You can hold your own in PRS with a few grand in gear. You are probably looking at $10k or more to get into ELR with anything that can compete at the upper levels. You can probably use ammo off the shelf for PRS but ELR require precision hand loading and all the caveats that comes with. You then need to be able to read the wind and correct for it. To top it off you need to have practice with ballistics solvers and know when not to trust them. ELR is an order of magnitude harder and vastly more expensive.
-Alex