I've found them to be very reliable esp. given the price they sell for.
They can be a great deal for either a commuter or kid's first car.

I don't know mpg off-hand.  It should be inline with comparable Civics
and Corollas.

No timing belt, it's a chain.  I think they are interference, but you
shouldn't have to worry about that if you change the oil.  They are
very easy to work on.

With a high mileage unit you would want to check for unusual engine
noises, sludge under the oil cap from lack of maintenance, poor
shifting transaxle (esp. a standard trans - this can be a sign of abuse
if the synchros don't mesh easily), leaking power steering rack, Check
Engine light on (find out why first) and finally do a basic safety
inspection of all systems before accepting the vehicle or commiting to
a price.

Toyota MDT in MO

From a mechanical point the car is probably very good.  The problem
is the company.  In 1999 it was on the verge of bankruptcy.  A massive
re-structuring followed.  Its future health may be uncertain.