Shed Renovation

Rustic! That would be the theme!
I would use what is SOUND lumber, reinforce what needs to be and give 'er Heck!!
Here in the damn S E Tx. Piney woods, last week a treated 2 x4 x 8ft was damn near $12. And that is at the yard right beside the mill that also treats it!
We can build sheds/garages out of steel cheaper than lumber and steel is up stupid also.
We can buy used 27/8 oil stem cheap enough.
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How much is the 2 7/8 oil stem pipe? How long is it? How hard is it to get?
I have a shed that needs rejuvenated also. It"s 24 x 40.