Some interesting feedback for that seller and I didn't have to dig very hard:
Transistors 5 times weaker than original.
transistor J13009-2 is not working properly
BEWARE: FTDI Chips FT232RL are fakes. They DO NOT WORK !
Sells FAKE FTDI Chips confirmed by FTDI inc.
www.atari8warez.com/fake.htmlFAKE 4X TRANSISTOR RD15HVF1 NOT WORKING - FAKE MERCHANT
I would say these 5101 RAM should be OK though as I buy them for about $1 each so that's the right money BUT unless you are buying from a trusted seller (as I do directly from their shop in Shenzhen) then you have no comeback really if there is a problem.
With that said $10 is hardly a huge issue if there are problems with them or some of them.