I have one from PLX devices . You can get a base unit plus a gauge for something like $269. You want the DM 5 Combo or a M 250 if they still sell it. Much smaller than the Innovate piece. It seems to me that the Innovate piece is more geared to temporary installations and is larger than the PLX piece. Here is the link
http://www.plxdevices.com/cgi-bin/sh...ategory%3DIMFD
Edit: Definitely worth it. Makes carb tuning a heck of lot easier.