I booked Enterprise a few weeks ago (thru Costco) for about $110 for Mar 8-13, now its over $400...yikes.
I know Enterprise and Alamo/National are the same company...is the rental experience with Enterprise similar to Alamo (kiosk, pick your car, etc.)?
Having gone in March for several years now, here's my advice: look around and book your best deal. However, DO NOT lock into anything (no prepay, no Hotwire, etc.). Rates are high now for March, but they will be volatile. You have to stay vigilant; the best deals I've seen are usually 5-14 days out... When you get that close, sometimes the rates change several times even in one day. Be patient, we've got over a month before the real rate hunting begins (but pay attention to my first point: book something now too...you never know)