If you need to replace a door, don't automatically head to the home center. At salvage yards you can find pieces that were built to last, like this 1920s heart-pine door with recessed panels and divided lights bought for $500. You'll likely need to remove layers of paint and sand out wear and tear, but it's impossible to find that kind
of old-growth wood nowadays. A reproduction would cost $1,300.
Bonus Idea: Save on an expensive lockset by using a $75 porcelain doorknob and brass plate with an $8 mortised dead bolt.