I bought my own equipment after 2 days of snowboarding. By that point I knew I would be sticking with it. Of course in my case the late-season sales had started so I paid 50% or less.
Here's a question for you: how much more do you think you'll pay worst case buying now vs renting for the rest of the season. $100? $150? Don't know anything about you, but how significant is that in the grand scheme of your life? Sometimes people get too torqued about absolutely avoiding any possibility of "losing" any amount of money, or making a decision that might be less than 100% optimal. Get over it. Unless the downside will cripple you, go with what will give you the most enjoyment. That's what life is for. The other thing is called "existing".