Suppose in some respects, it depends on which printer you are using...
I have four or five Epson printers and one Brother A3 printer, all of which accept compatible ink cartridges producing adequate results...
Some bought regularly at a computer fair - same trader - others from Amazon... All work to perfection and are at least half the price of OEM material - if not cheaper...
For the Brother, OEM around £30.00 a set - Amazon £17 a set with one extra black - computer fair, £12 a set of four colours - Black - Etc - Etc - Etc...
Naturally, one always takes a chance with compatible inks and if there is a problem with the printer and it's returned to the manufacturer - they may not accept any responsibility for any type of fault, if compatible inks have been used...
Hope that helps in some way...
Robbie_DL...