The line that matters is financeability
There is a threshold below which ordinary buyers cannot get a mortgage on your house. Below that line, your buyer pool shrinks to cash purchasers and renovators, and the price reflects it. Above it, you have access to the full market.
Items that commonly push a property below that line: no functioning heat source, active roof leaks or significant roof failure, unsafe electrical service, missing kitchen or bathroom fixtures, significant visible mold, broken windows, or structural movement. FHA and VA appraisals apply stricter standards than conventional.
Where money goes furthest
High return
Anything blocking financing. Fixing a $4,000 problem that unlocks the financed buyer pool is rarely a close call.
Moderate return
Paint, floor coverings, deep cleaning, decluttering and basic landscaping, if you intend to list.
Low return
Kitchen and bath remodels immediately before a sale. You rarely recover the cost and you are guessing at taste.
Negative return
Cosmetic work over an unresolved defect. Inspectors find it and it undermines everything else you have said.
The half-finished trap
The worst outcome is starting a renovation and stopping partway. A gutted bathroom or a partially replaced roof reduces value by more than the unfinished work would have cost, and it signals problems to every buyer who walks through.
Decide the strategy first. If you are going to repair, scope and fund the whole thing. If you are not, sell as-is and price it honestly. The middle is where money disappears.