Price of iPad

I wonder about the price of Ipad. I bought it about half a month ago, the price was 86500 inclusive of tax, and I got a 12000 gift voucher. And now its price is 10500 including tax. I don't really get it, I don't know what happened when I bought it, because at that time I didn't notice anything else, maybe this was a stupid question. Please sympathize with me. Thank you

＊　Retitled and Relocated by Host　Apple Inc.