Right now probably the cheapest you can find these set of DDR4 modules. These should be SK Hynix DJR modules, and Dual Rank.
Capacity - 32GB (16GBx2)
Multi-Channel Kit - Dual Channel Kit
Tested Speed - 3600MHz
Tested Latency - 16-19-19-39
Tested Voltage - 1.35V
Registered/Unbuffered - Unbuffered
Error Checking - Non-ECC
SPD Speed - 2133MHz
SPD Voltage - 1.20V
Limited Lifetime
Features - Intel XMP 2.0 (Extreme Memory Profile) Ready
Additional Notes - Rated XMP frequency & stability depends on MB & CPU capability.
Anyone know if they are cpu air cooler friendly?