Something I did early on in my cubing career, was buying a cube for almost every event as fast as I could. The problem with this was, I ended up with a ton of bad, super cheap cubes that I didn't really need or want to learn to solve. Since then, I have had a long break from cubing, and once I came back, I got a lot more serious about my cubing and started buying a lot better cubes. What I am trying to say, is that you don't need a puzzle for every event right away, so buy them at a slower rate and take other things about the puzzle into consideration, instead of just the price tag. This is mostly just advice for beginner cubers, but for more senior cubers it is still important to check reviews and if possible try the puzzle at a comp before you buy it.