As someone who regularly builds/repairs hydraulic hoses at work, unless you're making up 1000's of feet of hydraulic assemblies every year, the expense of tooling up to make them yourself is cost prohibitive. OP never mentioned what size/length hose he had made - $400 could be very reasonable. On a 4-braid hose, the fittings alone could come to $250 or more.
The dies are manufacturer specific (Parker, Gates, Aeroquip, Weatherhead) and each size hose takes a different die set. Our Gates machine uses a tapered cone and die set and pushes down on the cone that squeezes the die (similar to a compression fitting). There is a micrometer-like switch mechanism that sets how far down the cone is pushed before automatically turning the hydraulic pump off and controls how small the fitting gets crimped. Different series of hose in the same size require different settings on the crimper to ensure a solid crimp - i.e 2-braid Global Spiral takes a different setting than a Non-Conductive hose even in the same I.D. size and using the same fittings. Gates also has a chart for using their fittings to repair another manufacturer's hose - I would imagine most other manufacturer's offer similar.