Should I wait for DDR5 prices to drop further before buying?

Probably not. DDR5 has already fallen 40-50% from launch, and mid-range kits are now close to DDR4 prices. Further drops will be smaller and slower — maybe another 10-15% — because manufacturing is maturing and DDR5 is becoming the standard. If you need DDR5 for a current-gen build, there’s not much left to gain by waiting.