Dictionary / Vocabulary / 買い足す
かいたす
to buy more (of something)
Also written 買足す
「ワインは何本注文すればいい?」「手始めに10本注文して。必要ならいつでも2、3本買い足すことができるから」
"How many bottles of wine should I order?" "Order ten to begin with. We can always buy two or three more if need be."