Question: how much does it cost to update an electrical box?
Answer: Cost to Replace or Upgrade an Electrical Panel. The average cost to replace an electrical panel is $850 to $1,100 for 100 amps, or $1,200 to $1,600 is a new service panel is needed. To upgrade to 200 amps, expect to spend $1,300 to $2,500, or $2,000 to $4,000 to upgrade to 400 amps.