I agree that you should go with the 50A. That's what we did. Granted, we won't likely ever use the full capacity, but that's how my trailer is wired, so that's the plug I had installed, and I'm glad I did it that way. The upsides are that I can run my trailer at it's full potential right in my driveway. Primary concern is the AC, it gets HOT down here, and loading up or working on a hot trailer in August is NO FUN.
I guess I don't understand why the cost difference is so significant? Is a 50A box really all that much more expensive than a 30A? The labor cost to do the wiring should not be significantly different? What gives?
I would still go with 50A, but the cost increase sounds a little fishy to me.
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!