I've been using my Tronographic Rusty Box as a studio and live preamp for dirty/saturated/OD tones, and it has proven a wonderful tool for this task. My guitar player recently bought me a wonderful 100-watt all tube amp, and as such, my dirt needs have been covered.
Tronographic is currently selling these for $185, plus $15 shipping to the US (i.e. $200). You can buy mine, which is in nearly new condition, and includes the 30V AC adapter for $165 shipped to the lower 48. Paypal or money order preferred.
Here are some soundclips I recorded with the Rusty Box, with a parallel track through a Radial JDI for comparison:
Tronographic Rusty Box Soundclips 