I’ve had good luck with Ebay. I got two 5TB enterprise drives that were SMART tested and from a trusted seller for $100. I’m in the US so YMMMV, but I’m pretty sure Ebay is global.
Also to dissuade your fears: Ebay actually has really good buyer protections now, and a good reputation system for sellers.
I have a paper calendar on my wall. It’s really nice because I find writing things down helps me remember, and also because you can get ones with different pictures or jokes or facts or recipes on the other side, so you get a new set each month.
Also if you follow two calendar systems it’s particularly nice because they can both be on the same calendar. (For example mine is a combined hebrew gregorian calendar, which is much nicer than just having the computer tell me when holidays are)