3 Stepper Driver Circuits on one breadboard?

Last week, I spent a pretty good amount of time looking into how to make the cheapest stepper driver circuits possible.  As I've said earlier, I was really shooting to keep the whole project under the $300 mark so spending over $100 on just the 4 stepper circuits (X, Y, and Z axis along with the pinch-wheel extruder) was not really an option.  I experimented with using a programmable IC to control the motors.  A 14 pin PICAXE 14m can be had for just over $3 and has more than enough I/O pins for the task.  I did some research and actually came across a instructables site with code for a PICAXE 08m for controlling a stepper motor (link:http://www.instructables.com/id/S21HCCVFBVHERQQ/).  Two things to note here:  1.  The motors have to be run in bipolar configuration otherwise a pretty good amount of additional circuitry would be required.   2.  high power MOSFETs (HEXFETs) are used in combination with the PICAXE output pins to allow for high current flow (up to 50 Amps in my case, $1.02 each).  Using this technique you can get a working driver for under $10.  

Drawbacks:  The driver worked but timing was not always as precise as I would like.  There seemed to be a decent amount of delay between the trigger pulse and the HEXFETs firing.  The main reason that I got rid of this was just that it was too slow.  The PICAXE chips are great for simple stuff, but anything requiring high speed/precision, you probably want a different chip.  

After asking around on the reprap forums I was directed to check out the StepGenie stepper driver chip (www.stepgenie.com).  The chip costs only $6 and basically does exactly what I was trying to program my PICAXE to do, but much better.  It has modes for high torque, full stepping, and half stepping.  The only inputs required are a step and direction pin (typical for these boards).  I ordered one with 4 HEXFETs and quickly got a working driver that was performing much better than my old attempt.  I had a few issues with the HEXFETs heating up.  The particular flavor that I ordered were just barely turning on at 5V and then trying to push 2 Amps of current through it was causing issues.  I opted for FDP8447L FETs that would allow more current at a 5V trigger.  When I was convinced the whole thing worked I ordered 3 more StepGenie ICs and 16 FDP8447Ls.  The cost for the components for all 4 boards was just over $40.  Here is a shot of my XYZ stepper circuits, along with my thermocouple circuit (which finally arrived!).  

I am making a LOT of progress on the mechanics of the machine as well, but I'll leave that for another post when I have more time to type it out.