You could probably have paid less if you had been willing to wait for the right opportunity. That's MS64 money, judging from the last two which sold at Heritage earlier this summer. However, those are the only two in that range that Heritage's archives show.
ebay is equally sparse.
Among those who are "in the know," 3CN's are among the most undervalued coins out there, and yours is one of the scarcest of them. I think the population figure of around 500 higher than yours (PCGS+NGC) is unrealistic due to crackouts, because grade values increase rapidly with this coin.
So, did you pay too much? Probably. Will it come back to haunt you? Not at all, unless you try to flip the coin in the next three months.
One thing we tend to overthink in numismatics are coin prices. We tend not to remember that prices are
completely market-driven, i.e., in all cases the buyer determines what a proper price is. There aren't government controls or anything like that here - there is only the guy with the wallet, deciding how much he wants the coin. Price guides are only reflections of previous sales, or wishful thinking on the part of the guide publisher.
With that in mind, for this coin, there is no "right" price. There is only what the buyer feels is a comfortable price.