gia vang hom nay 23 4 tren thi truong the gioi o muc thap nhat 4 thang bat chap gia dau co xu huong tang len gia dong usd cao cung la ly do tac dong toi vang gia vang trong nuoc dang cao hon gia vang the gioi khoang 1 trieu chua tinh thue va phi