Calculators you regret not buying?

[esm]

Hi, I'm new on the forum but I've been interested in calculators for a while. I started with Casios when I was in high school and college (2000s). I eventually got into HP calculators after learning about RPN (I'm also a fan of HP's lab gear and test equipment).

I used Free42 for a while before buying my first HP calculator, an HP-32S. I really liked it but not as much as the 42S with it's dual-line display and better complex number support. I eventually got a DM42 in 2018. My most recent purchase is an HP-15C CE which I'm really liking. I love the continuous memory of HP calculators, something that my Casios never had.

I had considered a 35s a while back when I was first getting into RPN, but I read that it was 'buggy' and decided against it. Now that I'm getting back into calculators, I thought I should buy one only to learn that it was discontinued! New-in-box 35s's are now commanding fairly high prices on the 2nd hand market.

So my questions is: Which calculators do you regret not buying when they were available new? And which current calculators do you think will be future classics?