Never bought an original Epson cartridge, I only use compatibles.
The quality of the ink can vary greatly between cartridge manufacturers, as you would expect, but with some producers there is no consistency between batches of ink.
The most consistent that I have found is jet tec. The colours are not quite as bright as epson but at the trade price I pay I do not care.
The cx5200 uses chipped cartridges which need to be reset if you decide to refill them. If you want a link to the required info let me know & I'll pm it.