Agree with the above input. People typically want a kit because they enjoy putting it together and the cost savings is an added plus. I'm sure it's a small percentage of those needing replacement boards though.
Just looked at Pinballlife and they offer two kits. One is $60 and the other is $70. They come with connector rebuild parts included. From my glance the higher price one also provides the plastic fuse cover and one power-on indicator LED.
I think your kit for $50 shipped is a good price.
I could be wrong but when people ask for replacement board suggestions I don't recall the Pinhead board being mentioned. Maybe put it and the kit in the Pinside Marketplace to increase visibility. GLWS