When I started flying back and forth to BBK I bought the tickets for economy or the cheapest fare. The second time I went I upgraded to first class at check in. Then other times I would use some miles and cash to upgrade to first. I think that is why I obtained gold status. Otherwise even with 20,000 some miles would never get me gold. I wish I never tried first class because you never want to go back to economy! So I do a little of both.