The engineering, permitting (if even allowed) and concrete work to properly put in a pit now-a-days would not be DIY thing or cheap. Cost should not be the primary deciding factor though.
Why would you ever need to put a tractor on a lift?!? Sounds pretty silly considering that one can get all around a d under a tractor just as it sits .
I had a pit and loved it. I have a two post lift now but wished I had a four post if not another pit. No weight limit. No falling off. I was on a hillside so it had a drain. I had a built in shelf with air and water connections. I used a ladder but later laid blocks for steps. I never put a cover over the pit but you could.
I am stealing that idea.
I would definitely do a lift. I had a three Rotary four-post lifts and loved them. I was able to stuff seven collector cars in a garage built for three. A sliding pan system catches oil, so no worries about drips. I would think a pit would always be in the way when not using. Personally, I would not be comfortable putting a tractor on a lift because of the weight, unless all the numbers showed it to be safe. (I have a series 3 John Deere, no longer 1026R.)
I recommend avoiding cheap lifts from China. And avoid making the same sort of dumb mistakes people do with trailers.
All I got to say is that the pit will always work although you need to install ventilation in it.
