well, good luck but i really doubt how there can be a profit in it.
h&m are a VOLUME mass market retailer. all the talk of limited edition is quite frankly bollocks. for as long as there is demand, they will have the supply.
when there are only selected stores only selling them. there will not be mass VOLUME in stock.
the knee high boots are only availble in 2 stores in the uk
so i dont think there will be enough boots to supply the whole demand