For that matter, if you can buy arcade bits (sitcks, buttons etc) it shouldn't be too hard to make your own enclosure and everything, looking at the way they've built theirs.
A moulded plastic 'cheap' enclosure might not be so easy, but if you take a look at
http://www.lemon64.com/museum/view.php?id=77&genre=advertmisc you can see that a very nice joystick can be boxy and best used on a table top. These things were the best Amiga joystick I ever used.
tiffers