Conversation so far:
how many keys on a concert grand piano
Most concert grand pianos have 88 keys.
which piano has the most keys
The Australian piano manufacturer Stuart and Sons manufactures a piano with 102 keys!
how many keys does the imperial concert grand piano have
The Imperial Concert Grand Bosendorfer piano has 97 keys! On this particular piano the extra keys have the colors reversed.
how much does the The Imperial Concert Grand Bosendorfer piano cost
The Imperial Concert Grand Bosendorfer piano costs between US$256,000 and $560,000.

Question: what does the cost depend on
Self-contained rewrite: what does the cost of an Imperial Concert Grand Bosendorfer piano depend on