When my wife and I were renting our first house after we got married, I told the landowner to give me first dibs at a chance to buy it if he ever decided to sell. I didn't want to change our existing relationship, but to respect the relationship we had already established and just give me a shot. He did a couple years later, and though I ended up buying elsewhere (I found I could get more for my money elsewhere), I thought it only fair.

I would think you could ask something similar of your landowner with no hesitation.