Cashmere is stratospherically priced in most tailored clothing these days unless it is mixed with less expensive fibers, but there remains one relatively affordable application for it and that is the odd waistcoat. Done, for example, in cream and preferably double breasted like the version on the spat wearing fellow in the illustration, the odd cashmere waistcoat adds depth to a variety of fall ensembles. Wear it under a jacket that has some white in the weave, such as a glen check or a chalk stripe, to blend it in.
Now the odd cashmere waistcoat is only more affordable because it requires significantly less of the precious stuff than do jackets or trousers, and that may be why Beau Brummel himself chose it for his. Just half a meter will suffice for most men as the back of a waistcoat is usually made from Bemberg or other lining material.
That puts the odd cashmere waistcoat in the prudent expenditure category for the imprudent among us.