The “sport” is one of my favourites and I urge you all to give it a try.
I would be careful about playing at licensed card rooms because the advantage is theirs, and if you lose what you pay for, you will end up finding yourself paying more until there is a cap.
If you play with your friends, I would recommend no more than £30 per week. Some of you may not want to get involved as often, so perhaps a £50 to £100 buy-in every 6 to 8 weeks? From there, you can decide whether or not to play a tournament.
As for me, I need to teach Sir Trump a thing or two about the meaning of Las Vegas. Perhaps someday? I don’t know. Casinos forever? Yes, and we all need to indulge every now and then.