noun
Often pejorative; refers to someone who buys limited items (tickets, goods) to resell at a profit, especially online.
転売屋がコンサートのチケットを買い占めた。
Scalpers bought up all the concert tickets.
限定品が転売屋に高額で出品されている。
Limited items are being listed at high prices by resellers.
ダフ屋 specifically refers to ticket scalpers, while 転売屋 can cover any type of reseller.
Compound of 転売 (resale) and 屋 (person/establishment).