I paid $50 for a gutted Virtual On cab without a monitor, but ended up with around $750 in it by the time I repainted, built the PC, added a PC steering wheel, etc. I recently picked up an Initial D with working monitor for the same price, but it was from someone who just wanted it out of the way.
If I had it to do over again, knowing what I know now, I'd hold out for a Daytona or Sega Rally Model 2 cab and build Aganyte's interface utilize the original controls.
http://translate.google.com/translate?hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=fr&tl=en&twu=1&u=http://www.gamoover.net/tuto/l2m2-interfacer-un-ffb-et-volant-sega-model-12-avec-un-pc-ou-une-playstation-23 People seem extremely pleased with that particular setup.
There isn't a hack out there to use the force feedback motor in crazy taxi, so you're looking at building a new dash for a PC wheel, or buying a different arcade wheel and trying to hack it into that dashboard. If you're ok not having force feedback, you can just swap potentiometers in that wheel and use it as it is.
Most of the time you go have to roll with the cab that presents itself though.
For that cab, at a minimum you're looking at:
1. Building a PC with enough horsepower to run the games you want to play.
have a look here:
http://forum.arcadecontrols.com/index.php/topic,130988.msg1342049.html#msg13420492. Interfacing the arcade monitor to a PC if it works. If not, squeezing a TV in place of the monitor
3. Replacing the potentiometers on the steering wheel and pedals with ones that work for your chosen interface.
(u-hid, Logitech wheel hack, etc. See stickied driving cab thread) You will have no force feedback.
--or--
Hacking up the current dashboard to incorporate a PC wheel such as the Logitech G27.
That cab only has an Up/Down shifter, but there is a software solution that will make it work just fine on the Sega 4 speed games.
Browse through the stickied driving cab example thread and see what others have done.