When our macerator locked up a few years ago, I got a similar price on the replacement.
Instead, I purchased the entire Groco tank assembly for a few hundred more. But it was 50% larger in capacity (same height and width, and seven inches longer), and was the SweetTank model. That means it comes with a high-volume, low-pressure air pump and has an air distribution manifold in the bottom of the tank. Haven't had to add any chemicals since, as the aerobic environment in the tank will not support the stinky bacteria that need an anaerobic environment.
Tank is mounted athwartships, so no problem with the extra 7" length.
Brian