I am going to replace the main panel and also upgrade it from 100A to 200A. The electrician charges me $200 for the difference b/w 100A and 200A box. I thought the difference is just the price for the box but he said he must use with bigger wires also and other parts. I am not sure if he replaces what needed or he tries to do more than required to charge me for the extra? Thx.

I have a 240v/50amp service to my spa but the spa is only 120v so there is an extra #8 wire that is capped. I wnat to use this and the common and ground to provide power to a new sub panel for outdoor lighting, fountains, etc. I can connect to this extra wire in a junction box and extend the common and ground from the spa's buss bars. My sub panel has space for 2 breakers ( I'm using a 20 amp and a dbl 15 amp breaker ). Should I run separate wires (what size to the hot busses from the existing or should I run 1 #8 wire and split/jump within the sub panel box? If I runs separate wires about 20 feet, what sizes would be appropriate for the 2 breakers? What is the best way to ground this new sub panel? Ground Wire to a clamp on a pipe or rebar driven into the ground or set in concrete? Thanks, Joe