You would need to provide a little more detail about what type of air plane you are asking about. Two engine, jet, lear jet, cargo plan, model, age, etc. You could also see what they are going for by looking on line for air crafts that are being sold privatinly or by company's. I believe there is a magazine on air crafts that probly have a listing of people buying and selling air crafts as well. I know this doesn't answer your question but it may lead you in the right direction to get your answer at least.
As much as you can possibly get.
the elevator is what makes the the aircraft go up or down.
The plural of aircraft is aircraft. Much like how the plural of deer is deer. (Singular: That is such a beautiful aircraft / Plural: Look at all of those aircraft)
There can be hundreds of thousands of bolts on an aircraft
It depends on the type of aircraft
make an hour for painting aircraft
You would have to specify a particular aircraft, "fighter aircraft" is too broad a definition.
The maximum height flown by an aircraft is 37650m(123524ft). The aircraft is Mig-25 Foxbat.
It depends on the size of the aircraft and the power of the engine
Both prior training and the years of experience will be a factor.
As aircraft go higher the air becomes thinner reducing the energy required to push the aircraft forward
Since aircraft do not, and in fact cannot, go into space then it should be obvious that no aircraft has ever been to Mercury, as yet.