$754 for a catalytic converter and resonator hardware for a 1.8L 4cyl. 2004 Toyota Corolla?

That is probably $754 too much. It is very unlikely your 7 year old car needs a converter, and if it does (and the mileage is under 80K and it was originally sold after this date 8 years ago) it is under the federally mandated emissions warranty if you are in the US.

My guess is that you are looking at a new converter because of a P0420 code, "catalyst efficiency below threshold (bank 1)." That code seems to point an accusing finger directly at the catalytic converter but it is really saying the converter is unable to digest the exhaust. The most common causes are a leak in the intake manifold, an exhaust leak, a bad O2 sensor (possible but not very likely at 7 years old), or dirty fuel injectors. I recommend starting with fuel injector cleaner and if the code does not go away and stay away after a week or so have the intake and exhaust checked for leaks. If still no go, replace the forward O2 sensor. The converter should be the last thing on the list.

One important thing about Toyota exhaust systems - they are stainless steel and will far outlast ordinary steel replacements.

The '04 Focus has gotten a lot more reliable than when the Focus line started back in '00. The Corolla has always been king of cheap reliability though. While both cars are in the same class, getting decent mileage and reliability, the Corolla would still be better in those two, by a bit. However, with a Corolla, it's not anywhere close to being as fun, and it's much slower than the Focus from what I remember when driving them. The Focus is a lot more sporty in terms of acceleration and handling, though, I might be wrong about acceleration, but it sure felt a lot faster way back when my brother had one. So, if you enjoy spirited driving, get a Focus. If it's all about gas and reliability go with the Corolla.

5 year old car with failed emission part? These parts are covered under manufacture for 10 years or 100K miles. If you need one, check out the local muffler shops. The can just weld an after market one on there for a fractional of the price! Your mechanic have to make his share of $$$ for sending out your car to a muffler shop.

Again, don't call your auto mechanics for price. Check the yellow page on the telephone book and call the muffler shops for different price.

Not only high, especially for a Corolla, but are you sure you ACTUALLY need one!? Get a second opinion.