It's good that you were able to visit so that you could make a definite decision. The money factor is a significant consideration to take into account among all the others. Enjoy your time at UCLA. (The Williams president's wife is a screen/scriptwriter, and is able to work from Williamstown on the TV shows/movies she's involved with.)
I'm glad that you were able to think things through and make the best decision for you. Your story highlights how crazy the "which college should I go to" threads here on College Confidential are. Simple truth of the matter is that a good decision is always based on individual preferences and priorities. Money. Location. Weather. Size. Diversity. And, and million other possibilities -- none of which anyone can answer for someone else. You could have been sitting next to someone on the plane home who made the exact opposite decision and you both could have been 100% right.
Gather information. Visit. Think it through. Ask your gut. Make a decision, knowing that its a win-win when talking about two good schools like Williams and UCLA.