Ofc. they do. Console market is one example. And cases where a company uses dumping strategy to weed out competition and than raise prices dramatically.
As guy above me mentioned Rorqs and “gun mining” is one reason. As for “no profit”… i’d argue… if someone stocked up on parts at 30% price last year, before a patch or something, hes making profit building out of the stockpile even thou current part prices vary. It takes time to chew trough stockpiles.