When I was looking to have my Supra seats redone 2 years ago, I couldn't find anyone in the area willing to do it for under $300/seat.  You might look on the sac craigslist, there are a few ads on there w/one, claiming to be the cheapest in town.  If the cushions are still good, you can get oem quality seat covers for about $200/pair.  The cheapest solution would be swapping in some 2nd or third gen Runner seats, or buckets from a 3rd gen truck or Tacoma.  If you can't find a decent set, you can use two passengers seats and one drivers(non-power) seat, and swap out the good passenger seat back and bottom with the drivers.