Ouch, that's a lot for a Mako but it's also the nature of collecting. I reckon you were right to choose BIN: You would most likely have been beaten to it if you put in an offer.
I just checked my records and yellow Makos were going for $180-$285 on eBay.com in 2014. Oh how things change. Why didn't I buy one back then!?
I agree. Prices for all Makos are creeping up. They're not exactly mega-money of course but, like SKXs, they're going higher due to perceived rarity as new models come in.