How to get stronger and healthier bones with little budget for supplements?

Diet, exercise. Bones grow in response to the stress place upon them. You need to walk, walk and walk. And do exercise routines that are readily found on line. Your diet should be rich in calcium, add vitamin d, and eat a low fat, broad range diet. Most should depend upon these facts for their bone health and not rely on supplements anyway.
Diet and exercise. That is it in a nutshell. Supplements are very over rated so due your due diligence.