Built, not bought is the way to go. In your original question you asked about just the boat, no goodies. I would think you would have no problem buying the wood, glass, and epoxy for the 50K you mentioned. If your budgeting a full build be reasonable, make a few calls. Just my outboards and the associated rigging was 30K. I ended up more than 3x the proposal I showed the wife.......But have you seen my boat?
"Sorry, Dear ... no birthday present for you this year ... and, er, uhhh ... no Christmas present either... Hey! Wanna go fishing!?"
I got about 110k in mine with nice new tandem aluminum trailer designed for a GA (its for sale) very well outfitted with 1242SVX Garmin gear including a invaluable auto pilot with seperate GPD tracking to drive the auto pilot flawlessly, color tracking HD radar, 65 gallon bait tank, outriggers, tuna tubes, Separate pumps for both, eclectic flush toilets for the ladies, sleeping for at least 3, 2 burner cooktop, grill that fits in my rod holders and enough hose to reach anywhere on the boat. , frig/freezer, sound system, full solar panels, never need to plug into shore power, Smart charger for both acid start batteries and 2ea. 100 AH lithium house batteries, dinette, rain water catch system on the roof, windless, euro transom, custom made rod holders, bow thruster, and a lady catcher she is!!!! Custom windows with screens, sliding wheelhouse door., lockable side rod lockers on the deck, Underfloor fish hold, Fish Fighter sliding rod holder system, 162 total gallons of fuel, 30 gallons of fresh water,
oh did I mention my bow thruster this was a must have for me, intermittent wipers, 48" super bright light on the roof, Bluetooth battery monitoring system, smoke and carbon detection, Cuddy and cabin cab lights, great AIS Lowrance radio, dual antennas. You could not touch this boat in a factory made boat for less than 450K. Drove it safely from San Diego to PV, 8 days and nights down the pacific side of Baha 1350 miles. Oh BTW the Black Marlin still holds the largest Black marlin record for the last 4 years at 450# My lady friend is just that were a good friends, I here she has a cute sister:)