1 Typically it costs $800-$1,200 to have a qualified electrician upgrade an existing panel to 100 amps, or $1,500-$2,500 if a new panel is needed. 2  Expect to pay $1,300-$3,000 to upgrade to 200 amps, or $2,000-$4,000 to go to 400 amps.3  Installing a new sub-panel runs $500-$1,000.ust a note on panel upgrades. For a majority of the states electrical code panels (2011 National Electrical Code), when upgrading a panel, a majority of breakers must be replaced with the Arc-Fault type. this may increase the past cost of the job by as much as $50 a breaker.