I made the conversion from AE to Carmina years ago when Carmina was consistently in the $400 - 500 range. AE is a great quality shoe with some aesthetics that leave some people wanting more. Meermin has nicer lasts, but the quality is hit or miss with poor customer service. I came to the conclusion that you were always better off spending the extra $100 to get Carmina over Meermin, if you wanted a step up from AE. Everyone complaining about the Carmina price hike was spoiled by the last year's ridiculously low prices.
If you absolutely can't go over 4 bills, AE is the way to go for a big clunky longwing. If you can find a good pair of seconds on sale, then you're even more golden.
If you can stretch the extra bread, then the Carmina is worth every penny even at 450. Just as long as you have your sizing down.
I would also consider Alden calfskin or grain LWB if you have more generous feet, though it's more expensive, and maybe not quite as nice as Carmina.