For me, it's a question of how much trouble-free operation equipment can deliver. View cameras are intrinsically durable, particularly if used by enthusiasts and treated with reasonable respect, view camera lenses and shutters will last indefinitely with a shutter service maybe every 25 to 30 years, given moderate use, and immediate treatment as soon as any mold appears.
For equipment subject to wear, however, new beats old every time. I know that some people use old SLRs apparently successfully, I have always found vibration levels creep up with these, so my policy for some time has been to buy a new 35mm Pentax, use it for 10 years and throw it away. This is the camera I use for very occasional press work and equally occasional wedding photography (friends only), nothing like TTL flash, motor wind, AF and matrixing metering for these situations. Similarly, for studio work with models, where film is wound at a furious rate, I have an RB67 outfit bought new and would not be happy using a much older camera. Since I do studio work only occasionally, the camera (now 10 years old) will probably last another 15 to 20 years - some pros shooting 30 or 40 rolls a day will turn an RB67 to junk in 6 months.
Some one mentioned motor drive - my answer to this would be that a motor drive is an embarrassment most of the time (heavy and noisy) but vital for sports (which some enthusiasts like to do as a hobby) and handy for some other things (any situation where you are using a remote release, for example).