Thanks for all the feedback, it was really helpful!!
Lou- No, I mean on the actual beach. I'm going to St. Augustine, Fl and I remember the last time I was there seeing lots of people riding their bikes on the beach (not sure if these were cruisers or not) and I wanted to kick myself for not bringing my own. The sand at St. Augustine is packed really tightly since cars are allowed to drive up and down the beach, I remember it felt like walking on concrete.
There's no way the people I'm going with would be cool with me lugging my giant bike with me so that's why I'm opting for a smaller folder.
I'm bidding on a Dahon Boardwalk s1 on ebay right now with hopes of closing in on this one around $180ppd. We'll see what happens. I've come to the conclusion that finding a folder under $100ppd given the time frame is a pipe dream.
Also, I'm more partial to a Dahon because I feel like I could sell it when I return from my trip and get back what I paid for easier than any other brand. They seem pretty popular on ebay.