Looking to buy a wsm

I have a 14.5 wsm and I think I want a bigger one. I know the 18 is $300 and the 22 is $400. It seems like one should just save up and get the 22 instead of buying the 18? But then the 18 probably uses less charcoal. Often I make one rack of ribs or maybe a couple pounds of chicken wings. The 14.5 is fine for chicken wings. But it is rather annoying trying to fit a rack of ribs on the 14.5, And sometimes if I need more wings for a party I don't have room. Does the 22 inch take up that much more charcoal than the 18 to make it a difference in price for buying charcoal? It seems like I might waste charcoal in the 22 inch. I guess for a small batch of wings I'll just use the 14.5, But for ribs I really want a bigger rig. Any thoughts?
thanks

The 22.5, for me, is perfect. If I need the space it's there. As for charcoal just use less. Overall I'd rather have the option to do more than no option based on available space. Pound for pound I think the 22.5 is the best purchase I've ever made with regards to outdoor cooking.

I made a smaller coal basket out of some expanded metal for my 22", if I don't want to use the included one. I use my custom ring twice. Honestly it is just less fuss to use the one that come with the WSM, fill it up ( it takes about a bag,) and when the cook is done, close all the vents, and then just re-use what hasn't burned on the next cook. Beside charcoal is pretty cheap.