Worst case scenario you can turn the tanks into a shelter until your missus calms down...
Learning generally boils down to "Repetition or the avoidance of pain", some people learn by doing, some by watching and some just have to pee on the electric fence.
Whether you think that you can, or that you can't, you are usually right. Henry Ford
Welcome! Now, to clarify...is that she won't let you sell two or won't let you keep two? My wife had a hard time when I built my trailer rig....but all the good food coming off of it has changed her mind a tad...tonight was smoked cedar plank halibut and ling cod.
In all honesty, probably not much that you would do on the 550 that wouldn’t fit on the 300. With that said, the 300 is way too big for an everyday pit for the family. How bout keep the 550, sell all three of the 300’s then build a really nice patio in the 120 range?
Whatever you decide, welcome to the boards and know that we are here to help.