Exterior breaker panel for adding a barn
I am adding a barn to my property and have an old home with a slightly rusted and corroded 100 amp breaker panel in a 4.5 foot crawl space that is currently grandfathered and maxed out. When my wife runs the dryer, toaster and another appliance at the same time she risks tripping it.
I'm adding a barn and want automatic overhead door openers, interior and exterior lights, workshop tools and eventually a space heater. My options are:
1. Run a new service from the pole to the barn and pay a higher rate for a second meter. Estimate $1300-1500, with higher monthly costs.
2. Keep the existing panel, run a new trench 150 feet from the house to the barn, and try to swap some existing breakers to get enough juice for the job. Estimate about $1300 for the work, risking breaking a corroded screw in the box and a bigger bill.
3. A junction box in the existing crawl space and moving the box 20 feet to a spot with 6 foot head room for a new 200 amp service, then a trench to the barn.
4. An exterior box for new 200 amp service with a trench to the barn. Electrician's estimate a little less than $5000: $2700 for the upgrade and $1300 for the barn plus $200 for the trench plus the cost of the exterior box, which I can't find anywhere on the internet but am told is expensive.
I have to access the box during snow, freezing rain or electrical storms and wonder if this is really a good solution and whether it might be more prone to quick corrosion. My wife doesn't want to put it directly above its existing location in the entryway. When I sell my house, the existing panel could be a deal killer for someone looking for a home with no potential problems and maintenance. Any ideas of what would be the better investment and most cost-effective solution?