I feel annoyed when I see it cheaper than the price I paid for it.
It's galling to see it being sold cheaper than what I paid.
Because if I see it being sold for less later on I feel annoyed.
「買った価格より安くなると悔しい」＝ I feel annoyed when I see it cheaper than the price I paid for it. / It's galling to see it being sold cheaper than what I paid. / Because if I see it being sold for less later on I feel annoyed.
ボキャブラリー
feel annoyed ＝ いらいらする、むかつく
galling ＝ 悔しい
see ＝ 見る
sold cheaper ＝ もっと安く売られる
the price I paid ＝ 自分が買った値段
later on ＝ 後で
イギリス 
