You always hear people say that everything's cheaper in Mexico...not true. While some items are less expensive and others are more expensive than in the U.S., overall, there's not a huge difference.

Things that are more expensive in Mexico than the U.S.:
peanut butter (nearly $4 USD for a small jar)
hair dryer (range from $40 USD to $400 USD)
microwave (the microwave we paid $50 for in the U.S. costs $90 here)

Things that are less expensive in Mexico than the U.S.:
electricity (but then again, it doesn't work when it rains)
books (we got all of Grady's medical school books (used) for $130 USD!)
tortillas (of course)