"My question is whether it would be less expensive in short term to have an electrician buy and hook up a gas generator, or whether it's better to wire to the grid."
My question - define "short term"?
A day, a week, a month?
If you're looking at having a pro come out to do the connection to the power point (generator or sub/panel in the outbuilding), the costs break down into several areas.
Hookup to new panel/new generator - roughly equal;
Cost of OH/UG service to outbuilding vs.
cost of generator AND fuel AND eventual grid power.
Fuel costs keep rising; and , since you mention "short term" it sounds like you're planning a grid connection eventually...why not just bite the bullet now?
You also mention the press is "a big one". In order to get a generator that can effectively and efficiently provide enough power for your press, you'll have to buy a unit that is sized accordingly...possibly driving the costs well above a grid connection.
(in other words, if the demand is 6400 w, don't get a generator w/ a max output of 6500w, since most "max" outputs listed on portable generators are very short duration draws, and continued operation at these levels will overload your generator)
[This message has been edited by DougW (edited 07-17-2003).]