I think you're making a few assumptions that need to be checked ...
#1 - The assumption that he has job security now.
In the industry where my hubby and I worked (electronics) someone who was around in the same position for over 5 years without a really, really good reason was considered old and stale. Not being moved up in position or transferred to a new challenge is a red flag. Also older or more experienced employees might be one of the first to get laid off when difficult times strike. There are two reasons for this. One is that management assumes that these employees will have an easier time finding another position. They lay them off with less guilt (backwards, I know). The other is that these employees tend to expect more (eventually) in terms of compensation and benefits. Older, experienced employees tend to be "high maintenance". Why keep them around when you can get a flexible person fresh out of college and filled with naive optimism?
#2 - The assumption that the survey is correct about what others in the area are earning.
I've found those surveys or websites to be wildly inaccurate in salary estimations in both directions. I also have never had a job that was so well focused in title and description that I could easily compare what I was doing to what others with the same title did even in the same company. In the end, when someone asks for a raise, the proposition comes with a demonstration of (a) how much value you contribute to the company - now and in the past - in dollars and (b) how easy you are to replace. There was once a point in time where I worked for a company as a programmer. I had customized a software program for them that ran their manufacturing system. They paid me a ridiculous amount of money to do nothing more than be "on call" to fix problems when they arose and run occasional reports. If I came to the office (I eventually was able to access the company's computer system from home), I mostly sat at my desk and surfed the internet. I put up with being suck in that position for quite a while because my company benefits were paying for orthodontia on two of my step-kids and hubby. As soon as that was over, I quit. They kept me in the position because they couldn't find anyone who was willing to train for my position (hello! dead-end job!) Within a year of my quitting the company sold out to another, larger corporation. Anyway, the point is, I was able to command that stupidly high salary because the company really had little other choice than to pay me if they wanted to keep operating. Salary is very flexible.
#3 - That you will stop living above your means if hubby is paid more.
You get that, right? It doesn't matter how much we earn. What matters is what we do with it.
Personally, I think you need more information.
I would research the cost of relocation. Can you sell your house and afford to buy another or find another rental? What would it cost to move? Keep in mind distance. A short move will be less expensive than a long distance move but a new employer might help with the cost of a long distance move. Also, a long distance move may be partially tax deductible. What is the difference in cost of living in any new area he is considering? (There are decent websites for this.)
Now, before he asks for a raise, he needs to quietly put out some feelers to see if a new job is even a possibility. Asking for a raise will signal to his employer that he is considering leaving. After all, what will he do if they say "no"? He isn't going to just quietly go back to his desk. He is going to be dissatisfied. So he needs to see if he can get a higher paying job elsewhere or even within the same company. To stay in the company, he can start making noises about wanting more of a challenge and the opportunity to take on more roles. Of course, with their benefit package, why would he want to stay? In the end, the best time to find a job is when you're already employed. As a matter of fact, in this economy, that is a wonderful time to find a job. Companies are seeing lots of resumes from people who are unemployed. It is refreshing to see a resume from someone whose job isn't at risk and is just wanting to get ahead.