Thanks for your kind words everyone. He arrived today, and I'd say he's lucky to be alive from the way the stupid seller packaged him! He came in this tiny little box that wasn't even marked "live animal", and he was in an even smaller bag that wasn't even big enough for him to turn around. I am SO mad.
He was barely alive when I got him in the tank I had set up, but he started swimming around within a minute. I'm surprised and disappointed, because the seller had good feedback for both buying and selling. Needless to say I won't buy from them anymore, and please send good fishy vibes my way..Hopefully Mr. betta will be okay from his journey.