I have a pc engine duo-r and when I went to buy the MDIN8's from monoprice they were out of stock.
I ended up getting some from solid signal. They were only 3$ per cable but are pretty much the same thing, mac MDIN8 beige cables.
They are pretty much the same color as the console and I have a white pc-e controller, so It works out fine
I would however not order these if you are not in the states.
I was charged more for shipping since I am from Canada.
They contacted my via email and asked for me to make a 2nd payment...
These would be cheap if you are in the US though...