减价 is a separable verb (离合词) meaning 'to reduce prices' or 'to mark down'. As a verb-object compound, 减 and 价 can be separated when you need to insert aspects (了, 过), durations, or measure words — for example, 减了价 ('has reduced prices') or 减一次价 ('reduce prices once'). It's commonly used in shopping, sales, and business contexts to talk about discounts or markdowns.