Bricks and static transformers like Norton & Superwarp describe above are hands-down the best price per watt even after you add a couple of PSX-AC units. 360 watts of power for $88 is dirt cheap, and you're still under $200 after adding two PSX-AC's for protection.
The ZW series are all good transformers and the ZW-L has developed into a status symbol when you consider the price per watt cost. The Z4000, while also a great transformer never had the nostalgic look that any ZW added to a layout. I know to my dad the postwar ZW was the pinnacle of power for his layouts not just because it ran everything but because of the look of the device. When he replaced it with a Z4000, he instantly knew it was better but the old ZW had to stay even if it only ran the trolley and some accessories. We tried to replace them both with a ZW-L but the modified sine wave from the ZW-L made his old postwar trains growl and run louder than normal, it didn't make the cut.
The best thing the Z4000 had up to now was the price per watt cost was better than any other high wattage conventional control transformer. If this is truly the last run of Z4k's and MTH is exiting the big powerhouse market, they sure are capitalizing on the demand.
