I'm not sure I understand. If desire to travel is the issue and you don't want to settle down, then there's really nothing that can be done about that, but with programming skills, as you said, you can work just about anywhere. I get the feeling that "major cities" is the real problem.

They are growing too quickly to make buying a place affordable in a lot of areas. A number of my coworkers grew up in NYC, but, as I've learned talking to them, would never be able to be afford to actually buy a place there. Where I live (around Hartford, CT), you would definitely be able to find a job with programming training and afford a house comfortably. You definitely wouldn't make as much money as in a major city, but that would be the trade-off. You also wouldn't have the same amenities, of course, as a major city, but it's easy to get to them on weekends.

In any case, you would definitely be able to afford a house with much less than a $25,000 down payment as long as you're willing to move.