RS wrote:

I just moved to Seattle and we bought a treadmill which we've kept in
the garage. Now the garage has a 15amp circuit but the treadmill needs
a 20 amp one. We asked an electrician to give us a quote to change from
15 to 20 and he has quoted $600 for the wall closet to the door and
$900 for a wall further.

I am novice at this, could someone tell me what would be a good price
to pay for this?

The material cost on this would be fairly small. The vast majority of
the cost would be in labour.

In any case, you should probably get a few more estimates.

Do you know anyone else there? Find out if they have had electrical
work done, who they hired to do it, and what they thought of them.

Chris