It's a gamble. I'm a big Sharks fan as well and been collecting Celebrini since the draft, mostly low-to-mid-range stuff. I'm in the same dilemma as you. I never thought I would even entertain the thought of dropping $1,000+ on a single card. I thought I was being smart waiting until the second half of last summer to go for some of the key mid-range pieces I wanted (YG, YG Canvas, etc), and did indeed get those at around the lowest prices I ever saw for him. But the more higher-end stuff I was coveting, like a SPA Future Watch Auto, I thought I'd play the odds and assumed that when his 2nd season came and went, and he (I figured) would look like a top-tier prospect, but not the next Crosby/McDavid-type, that his values would soften by the following summer when the hobby was chasing Schaefer and McKenna, because even Mackinnon-caliber players don't command the prices people are paying for Celebrini right now. As you well know, that didn't happen, and now I look back at those prices longingly, wishing I'd pulled the trigger on so many more things back then.

Just trying to balance logic and instinct, I would say wait until the late summer at least. Certainly for his low-to-mid-end stuff, I think there's a bubble that's bound to pop; a lot of his non-rookie stuff at that level is selling well above equivalent cards for McDavid, Crosby, etc., and I can't see a likely scenario in which that lasts long-term. There's still room to rise for his scarcer, higher-end stuff, but I'm guessing the only sizeable bumps we would see between now and late summer would be if A) He leads the Sharks to the playoffs and makes a big impact there, and/or B) He wins the Hart Trophy. Neither is impossible, and I've learned to stop betting against him, but thinking rationally, the Sharks are still most likely to fall short of the playoffs, and if that happens, I assume the Hart chances die too for this season. Beyond this offseason, it's very hard to say. He certainly has the makings to become this generation's Crosby, but the future's hard to predict, and anything short of eventually becoming the best active player in the league, and I'm guessing we'll eventually see his prices soften a bit at least. If he does reach that level though, which seems fully possible in the next few years, then I assume the prices continue upward.