I've owned nothing but Toyota's since 1989, until I bought my F-350 this past April. Never had any problems with any of them. I know a few people who had the MR2, and they loved them.
Get the VIN and check with the Toyota dealership. They should be able to run a check and see if it was serviced for any problems, regardless of where it was serviced at, so long as it was a Toyota dealership. Being an 03', I would think the previous owner would have had it serviced at the Toyota dealership.
If there isn't anything wrong, and you can get it that much cheaper than retail, you can't go wrong. If the wife doesn't like it after a while, stick it on eBay and sell for what you paid or more, depending on how long you keep it.
Hope it all works out.