Just got back from my honeymoon in Maui, and did a quick stop at a local store called Maui Comics and Collectibles. It was mostly comics, but they did have some NES cartridges available.
I picked up Super C and Metal Gear (with manual) for $18. I thought I was going to score Super C for the $3.50 sticker, but it was a from a box of new games that he just got in. I was fine with $18 though, happy to support the business.
Super C was $10, and Metal Gear was $8. Metal Gear is in top-notch shape, but Super C needs a cleaning.
And before anyone asks, I have a very supportive wife who allowed me to stop after I took her to a waterfall