From a purely financial standpoint, it absolutely makes sense. As others have mentioned, you just need to consider quality of life factors, and how those suit your own personal preferences and goals. In some instances, you can not only have lower living costs, but a better quality of life, too. I am currently in the process of making a move for the very same reason. We'll be able to sell our 700ish sq ft flat in London for about £320-330k ($500-520k) and will probably buy a bigger home in our new desired location - which is not only beautiful, but has a lot of amenities, opportunity and great people - for $200-300k. Because we own our place outright, we are really excited about the opportunity to free up some of the cash we have tied up and re-purpose the funds to other investment opportunities.
In our case, we also have the 'advantage' that our families are split between England and the US. Either way, we risk being far away from one set of parents, and knowing that makes us feel less guilty of moving much further away from DH's parents. Also, we figure even if we did need to move back to help look after them, we would be in an even better financial position by planning for our current life rather than planning in anticipation of something that may or may not happen in the future (them requiring our assistance).