If he is a Rothschild surely he can afford a Giorgi Mamani
Sure, I have heard he makes very fine suits out of Cui Skin
Anyway...when buying a suit it does not hurt having some - or obtaining in due course some- basic knowledge about fabrics.
In general I do not like fabrics containing synthetic fibers (apart from the fact that such a suit is indeed "cheap"). However, for Lima I would make an exception. The reason being that clothes with synthetic fibers do not that quickly become dirty when you drive or walk through Lima. However, suits containing synthetic fibers are very unconfortable to wear in hot weather.PS:
A suit designer from Gamarra which became quite famous in Peru (several known futbolistas etc. like to buy his designs) is Julio Cesar
. See for examplehttp://tiendas.gamarra.com.pe/ternos-julio-cesar/
His designs are "younger", not thaaaat classic. He also makes nice coats.