That is a nice and very expensive cage. The King's Aviary Cage like this one is a little over $800. This is the link if you want to compare it yourself. http://www.kingscages.com/ProductDet...ductID=ACP3325
. It's well decked out inside, playstand on top, and is very nice. He/She shouldn't need much if that cage comes with.
Elevenyears is not old for a Grey, but you'd need to meet this bird and see how it acts with you. Will she go to a stranger? Does this grey have a preference with men or women? Phobias? Why are they parting with it? I've seen them switch loyalties to a new owner when the old one is completely out of the picture and they're so lonely, so I wouldn't worry overmuch about that. You've got to meet the bird and as stupid as it sounds, factor his opinions into your decision. You can certainly overrule them, but you must be ready for them.
I knew a bird who was to be rehomed at about that age, and he was so cage-bound from not being handled that you could not touch him at all. Cleaning his cage without any attempt to touch him or look at him resulted in screaming and growling and throwing himself from side to side. In fact, he didn't like women, and would mutter in a low voice his opinion of me every time I passed his cage, and his selected word for me was a****le. He was a brilliant talker, and would happily initiate conversations with you. At one point the store owner stormed past, having one of her classic tantrums, and he called after her "Hey babe, chill out!" I wish I could have taken him home -- I would have in a heartbeat, but I had Merlin, mum had Alzheimer's, and none of us had any money.
As for how they are with other birds...mostly I've seen them ignore other birds. Merlin resents my Senegal and will go after him if they're out on top of the cages at the same time, so to protect toeses and noses we have separated stands for out time.
Greys are very loving, but not cuddly/demanding like cockatoos. They are quiet birds. They bond intensely. Some say they are sensitive and nervous, but I find that the more you cheerfully expose them to, the more easily they cope with the world around them. They read off of you, so if you stay calm and cheerful and laugh at what might be scary, they'll stay with you and relax. They are funny, and often use words correctly. My grey constantly surprises me with words or phrases, and I'll have no idea where she picked them up. For example, I have no singing voice, so I don't sing. But I sang a bit of a song I was listening to the other day. Merlin looked at me for a moment, then said "You're singing. Who are you?" I believe they know what they're saying and will converse with you. Or order you about.
They are a long-term commitment. I expect to have Merlin until I'm at least 75, which is what I counted on when I got her. I love having a grey. Mine is definitely a family member and it's like having another person around for me. I'd probably jump at the chance to have this bird, were I in your shoes, should the bird not be a total lunatic. I still regret not taking the cage-bound talker home when I had a chance. I'd say see what the bird's opinion is, and make your decision from there.