Not a mod retailer, but there are some classic labels in the End Clothing Winter Sale at much-reduced prices.
For a start (and unlike the maker’s own sale) there are a number of Fred Perry items, including the classic and Japanese polo shirts, not to mention Clarks, Adidas, Levi’s Vintage, Gitman Vintage, Sunspel, APC, Beams Plus, Gant Rugger, Mackintosh and much more. Basically, it’s worth having a browse of the 2000+ items.
As a couple of examples, this classic Fred Perry Original Twin Tipped Polo is down from £69 to £45, while the really cool Japanese Beams Plus Suede Type I Trucker Jacket is reduced from £435 to £285.
As I said, worth having a browse if you have time, as there are some serious bargains here (but you will have to dig, as the order is a bit random!).