You cant buy Battle Points from another player, you can tho buy items pruchased from them, if you need BP Moves you have to ask some one else to teach them to your Pokemon.
I know, I would like for our TC members to not advise people to move on to showdown when it's so hard to find matches at the moment.
Should've made that clear sorry.
Many tc members are not even on the top 100 there lol
Many of them don't even play the game, there are some names I haven't seen online at all. Like ever. And I play since 3 years