I don't think budgies are very good in with cockatiels as they can be too boysterous, and you can't get 2 birds and put them in a cage together and hope they get on, you couldn't do that even if it was another cockatiel you were getting! You would need to put them in seperate cages, but close to eachother, as suggested above. If you don't have space for another cage then I would let your friend find another home for the budgie.

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