Jeff, unless it is really cheap walk away, there is a reason the plugs are out. The timing chain could have failed and buried the valves in the pistons. If it runs thats one thing, why would a dealer have car in that condition and why have they not screwed plugs into it and tried to fire it. Dealers are not dumb just crafty, at 148K it could be anything.
BTW: compression tests are usually done with all plugs out, if the fuel system works it will pressurize the fuel rail at startup. The trick of spraying ether went out many years ago and has caused some engine explosions.