Digging Out Basement = Expensive

Our basement ceiling height is currently 79", but goes down as low as 69" in some areas (under beam/ductwork). We got a quote this morning for lowering our basement floor, which would include lowering the floor by one foot, underpinning the foundation, installing new drains, and increasing our supply line to 3/4". The quote: $37,500. Yikes! As much as I would love to do this, I just don't think we can afford it, and even if we could, I find it hard to justify the ROI for that type of expenditure. So, we are re-thinking that part of the plan for the basement. Should we just go ahead with the existing floor? Should we just get the basement drains replaced and floor re-poured so we are starting with a better surface? Should we consider options for lowering just a part of the basement, or get additional quotes? We might delay the basement project now so that we can think it through, and focus on finishing the first floor and preparing to do the backyard in the spring. We'll see though. Any thoughts? Has anybody done this type of work before? Has anybody re-finished their basement with a 6.5' ceiling and not hated it?