I have an '85, which has the same tank-size.
My fill-ups are usually around 10 gallons (The tank holds 17.2), so it costs about $35 to fill when you get town to about 1/8-1/4 on the gauge.
I get about 20 mpg with the 22RE--about 200 miles per fill.
I just looked at the link you posted. The picture on the page is a '90 or '91 2nd generation 4Runner, not an '89 1st generation (it's a pretty low-quality page). They both have the same-size fuel tank though.
Here's what an '89 looks like:
http://t1.gstatic.com/images?q=tbn:A...TKIM0gl8hvDL8Q