It really comes down to if you want buy a pre-made joystick, or build your own to your imagination. Either way you'll probably be happy, but I know I wanted to build mine. Kind of neat to see what you can do. I got all my parts real cheap. My trackballs were free, buttons and joysticks were free, particle board + wood I already had, screws I had, already had a jigsaw...come to think of it, only thing I really bought for my stand alone table top controls was a piano hinge from Lowes. About $8

::EDIT:: do'h, I forgot I bought the IPAC for $55...ok still cheap though

::END EDIT::
Now I'm building an upright cabinet, and yes, I had one already...but it's a Frogger, and I don't really feel like Mameing...er maiming...a classic machine. $55 for IPac after shippping, 2 joysticks and 20 buttons from xgaming on ebay for $28 after shipping (all black, very cool). Using the other free trackball...$8 for a 18" marquee light at Lowes, maybe another hinge...terminals about 15 cents a piece...Laminate's going to cost me big unless I cash in on a broken piece somewhere. Laminate cutting bit for router...Plus cost of particle board.
Sorry...rambling...

My opinion...build your own...you get a sense of accomplishment (and if you look in the right places/know someone, you can get the components much cheaper

)
~Mrbond