Having found a fair number of scooters, motorbikes, and cars in local publications for low prices, and fixed them up so as to be safe and reliable, to finally sell them on at a modest profit or loss (depending), I would call myself a hobbyist. Yes, I have “flipped” the odd vehicle that needed nothing, but most required some fettling and some required major investments. Friends helped me for free, and I helped them right back — knowing this is also a hobby. Six years ago, I relocated to a jurisdiction that allows five vehicle sales a year before requiring a dealer’s licence and submission of 12% sales tax, and reporting of profits as income, so I ‘throttled back’ significantly. Plus I lost both my garage and most of my mechanically savvy friends due to moving. Now I help others with their projects, for resale or not for resale, and acquire one or two vehicles a year to monkey with and eventually sell on. I have probably just about broken even over the years (even counting the 964 Carrera 4 that turned out to need a rebuild and that I walked away from, just before Porsche prices exploded), not counting ordinary running costs like insurance, gas, maintenance, and oil changes. I am certainly a middleman, finding and buying below market, fixing, sub-contracting, polishing, marketing, finding a buyer, etc. — but I am not a “flipper”. As for what’s driving up the price of collector cars: real estate. Nothing says “time to buy my dream car” quite like a few hundred thousand (or million) dollars in unearned windfall profits (untaxed in Canada) when us Boomers sell our long-since mortgage-free houses... flippers’ contribution to driving up prices is utterly negligible by comparison.
I personally have never bought a car - in ANY condition - with the intention of selling it. I've only bought cars that I wanted to own and drive. Maybe it's because I've always had pretty sparse disposable income, I don't know, but much the same as I don't like to gamble, I've always just felt that the purchase of a vehicle was/is just for the sake of owning that particular vehicle (whatever the reason).
Having said that, I have sold way more than a few vehicles - and even some that I've done some improving to. However, I do believe that I have NEVER - not even once - sold one for more money than I paid for it - or paid plus invested in fixing things. So, I suggest that instead of a "flipper", I must be a "flopper"!