Trailer tongue extension

I really think I am going to need a extension to my trailer tongue being that I am hauling and launching it with my Jeep Wrangler (short vehicle). I know the marina that I am keeping it at in a slip has pretty deep launch pads but I still think I am going to need one. The ones listed online are outrageous in pricing. This is so simple. It would just be an extension to launch and not while pulling the boat on the roads.

I was just thinking about going to the local welding company and asking them to just take a 2" square pipe about 4 feet long that would just fit in my Jeep receiver and then put a ball at the other end. The tongue weight on the 165 is light enough for me to lift it with one hand (empty anyway) so It's not that heavy.

Thoughts or anybody do this or something else cheap? I have searched online for a day for ideas but haven't found any really good ones.