That would depend entirely on the particular Toro mower you're referring to.
Kawasaki 15 HP Ariens Lawn Mower takes 1.2 Litres of oil and maybe a little more when you change the oil filter
Since you don't specify, I will assume you mean a power mower. A stripped-to-the-bones walk-behind power mower? $140 - $180. A bells-and-whistles self-propelled walk behind? $350 - $400. A lawn tractor? $1,000 and up.
Depends on the size of the mower.
6,250 J
That will vary for each make and model of mower.
It depends on what kind of lawn mower (push or ride). I sell my fixed push mowers usually for $30.
give up and hire a lawn service...
10 dollar
4 hp
about as much as a lawn mower
Check the oil/fuel mix and make sure you have it mixed to the correct ratio. Else, try raising the blade on the lawn mower. If you have the lawn mower blade too low, mowing tall grass, it can make too much work for the mower and will cause it to overheat.
It depends what kind? The push lawn mower about 70 - 80 pounds. The ones that you ride on, those weigh about 200 - 350 pounds!