I’ve put finding the perfect sweat to the back of my mind. The well thought of ones with correct detail (and sans fake US Navy type logo) are in the main just more than I want to pay for such a basic item.

If nothing else the ones I’ve tried on tend to be quite square and boxy. Being long in body they just hang wrong on me.

I have managed to stumble across two or three over the years that are okay. Mix doesn’t bother me hugely, haven’t checked but I think mine are 100% cotton. Light grey or navy only please. Definitely need that stitched overlapping ‘v’ on the neck. Raglan sleeve preferably.

I wore them over a T for years until it dawned on me that they look great over a bd with beat up jeans or khakis.

I think I paid around £80 for the Pike Brothers item.  That would be in about 2008 or 2009.
Colourwise, I fancied beige and picked up an old Levi-Strauss USA-made v-neck from a seller in Bulgaria.  When it arrived, though, the colour seemed slightly wrong and it was more like a poly/cotton jumper than a sweat.  So I let it go, together with (amongst other things) a Russell Athletic for L.L.Bean item that, examining it from every angle, looked plainly wrong on a chap of my advancing years - as though I might be on my way to smash up a 'phone kiosk or mug some old dear. 
The original - in mid-blue (almost navy) - although XL still looks okay, but may not for much longer if I shed more puppy fat.

I've got two plain mid grey sweats, one from Uniqlo and another that I bought in a Levi's shop in Brussels when we were staying and it was freezing and I hadn't packed enough warm clothes. They were both cheap and  meet my wants in terms of fit and detail. I've tried on expensive Japanese ones and they never seem to fit me very well and like Ian I can't see the value in them.

A 'Cheetah', on Ebay, was £4.45.  Including postage.