Wood beam

I have four pieces of 4x4 x 3/16 tubing 7' long in the backyard....its primed up and suppose to be used for the columns of a pavilion we want to build in the backyard.....My carpenter had a few things come up and couldn't start it this past fall
Now were seriously thinking do we want to spend the money to construct this as its going to be close to ten grand im sure, as moving may (or may not) be happening in a couple of years
I could use that tubing for the uprights and base. Id have to add a foot and half at least to the tubing I have but thats not a issue
Id probably uses a 3x3 x1/4 tubing for braces and than id need the I beam
Once I got everything together and then plates drilled im sure I could weld this up in a day
Im going to have seriously think about this and thanks for all the suggestions