The part about "the money was never the real issue" is close but not quite right for me. If she had told me straight up she couldn't pay it back yet, even for a year, I would have been fine with it. What killed it was the disappearing act while the beach pics kept coming. So for me the issue was both things, the money and the lying, and you can't really pull them apart. A lie about money is still a lie about you. She basically told you where you rank without saying a word. Good on you for sending that one text and not chasing her for an apology.

The "left a day early" thing is exactly why you gotta talk money before the trip, not after. I had this happen with a beach house a few years back, buddy bailed on night three and thought his total should drop since he wasn't there. Nope. The room was booked and paid for either way, his absence didn't save anyone a dime. Split it by nights you reserved, not nights you actually slept there. If the total was 310 for the whole stay, everybody owes their share of that full amount. Him leaving early is his choice, not your discount to eat.