How to not regret essential purchases?

This is a bit of a rant but this is the only place I could think of posting this.

I've been looking for an office chair for the last 1 month on Kijiji (canadian craigslist) but always ended up getting ghosted. I ended up giving up and buying a mediocre one brand new from a local shop (final sale, no return), and literally 4 hours later a dude who'd ghosted me finally messaged saying he can drop the chair off tomorrow (it's a better chair for a lower price).

This is really triggering my Frugal-OCD up bad. If I would've waited one more day I could not only have had a better deal but had a better chair. I've even been trying to figure out if I can sell this one and get that one but I feel like a normal person would just call it off and move on, right? I feel like I get super focused on stuff like this and ended up not doing stuff I should be doing. I don't really know why I'm writing this or what I expect to get out of it. Sorry. Thanks.