While searching the net for emission parts for a friend's Toyota, I came across a site that lists the lowest prices for SAAB oxygen sensors I've ever seen
For example, the one-wire type used on 1987 and earlier non-Turbo 900s is available as a Walker universal for $19.95, Bosch universal for $25.99, or Bosch OEM for $38. The 3-wire version starts at $46 for a Walker universal unit.
The site is www.oxygensensors.com
I haven't bought from them yet, but I'm posting this info hoping it'll save someone some money