ORIGINAL: Jeff489
They're in short supply right now. I saw a guy respond this issue on another tank forum. He has a hobby shop and had 2 TBU's in stock as of this morning for about $90 ea. I'm not affiliated with him, but just trying to help you out. Pm me if you want his contact info.
If you don't mind a little soldering a DBU cost $15.00 and is compatible with the tamiya DMD system, other then the plug, but the wiring diagram cover this.
Just another option