I have a used LM-1 for sale. Great for monitoring, logging, and bringing logs up on a computer to use for tuning/double-checking etc. This has been the standard wideband o2 for years.
Goes for $290 new:
http://www.gotboostinc.com/inlmbakitwib.html
$150 and its yours.
Secondly, I have an LC1, which is meant to plug into aftermarket ECU’s for continual on-board logging/tuning etc. This does NOT have a read-out. it is meant to be fed directly to an ECU input. Readouts can be purchased separately.
$170 new:
$100 and its yours.