Hearsay.........., comments from a grandson who is now a graduate engineer and due to spend his summer holiday charging down the hopefully snow free courses at Whistler B.C. He has done this three times already and D.G. survived with only scraped skin damage.
He told his mother on his first trip that he was spending more on bike spares and repairs than on food and day-day expenses.
He has spent a lot of money on what can be very expensive bikes some hydraulic forks around £1400 last year, though insurance helped.
So Fit-for-Purpose is your goal. If the use will be confined to special tracks in this country, or to charging willy nilly down a hairy Rockies slope will need thought, but carefully chosen second hand could save a pot of money, just so long as the purchase doesn't turn out to be about to collapse from metal fatigue or well hidden repairs