I have DDR4 RDIMM ECC 2400 16GB x4 and they cost a total of $450 and they were unboxed and barely used.
Prices for 8GB sticks should be a little less per GB and for non-ECC RAM a little less again.
If you pay $225 or more for quality tested and guaranteed 4x 8GB RDIMM then I'd say you're being ripped off.