I have a 224E and a 225E. Both are really sharp looking engines, and run well. I find the mechanism to be very quiet, considering that we are talking about a 3-pole open frame motor, plus E-unit operating on AC. The 224E is not a great puller, but I replaced the rear coupler and have been running modern rolling stock behind it, which is a lot less of a load.
You can run these on a command layout using a TPC or similar to vary the track voltage, but they really are happier running on smooth sine wave AC. If you use a conventional transformer, you will find that the motor, and especially the e-unit, is quieter. Also, when I run these using a Power Master (older than a TPC and reportedly not as good, so your mileage may vary) I have trouble getting the whistle to blow.
A reasonable price is a moving target - it materializes when the item you want and the money you are willing to part with show up in the same place at the same time. But for what it's worth, I bought my black 225E with die-cast 2235W tender about 2 years ago for $175. Engine C-7, tender C-6. Other than needing to be washed and lubed, the only thing wrong with it was a bad e-unit drum, and one bent tender step. I thought that was a pretty good deal.
