$1000 per foot has been a ballpark number for many years. It would not surprise me if it has gone up.
$1,000 a foot has been the price for over 10 years. Due to the U.S. economy and the slower demand for piano refinishing that price has stayed constant. Even though the cost of running a shop have gone up. $1,000 a foot is for a grain filled hand rubbed finish like a factory job. Not the open grain lumpy finish I see so often.
The last ebony finish I did for that kind of pricing was 2002.
Most cabinet shops who try their hand at piano finishing are ill equipped for the proper grain filling techniques, rubber button installation, and proper skills at dis-assembly. The result will be a piano that "looks" refinished. You should get someone who refinishes pianos regularly if you want it to look like new.
Rubber desk buttons and knobs can be found in a variety of places along with instruction on how to install if required.
The same goes for finishing technique and disassembly or reassembly.
Contracting a piano shop for refinishing is no guarantee of anything as can be read in this thread.
Steinway London