Customer wants an upgrade from 200 to 300 amp service. This is for a single family residence. Is the easiest way to change there 200 amp panel to a 300 amp panel ( do they even make one for residentil)and sub feed the 100 amp panel they want, which will be about 100 feet away. They are not upgrading because of demand they believe the house will be worth more when they flip it . I have done many upgrades to 400 amp and grouped the two 200 amp panels together. thanks