There are a lot of tech fabrics available now that can do a very good job of keeping you warm without having to pile on a ton of gear.
Indeed. I believe I have worn up to four layers, though typically do not wear more than three, and have never felt like a “snowman” or significantly weighed down. If one does it consistently, one will get used to it.
GoreTex is probably the ultimate for handling the rain and I've heard is pretty good for the cold. I've been too cheap to buy it, so I work with other, more affordable fabrics.
One can be cheap and still find it, if one knows where to look to find the bargains. However, I have not found that it is frequently needed, though that may not be the case in the upper lowlands.
For the rain, what I do depends on the temp. The worst conditions for running at all as far as I'm concerned would be 35-40 and rain. For this, I usually wear a pair of lightweight Nike Dri-fit or adidas Climalite pants and a similar shirt with a Dri-fit windbreaker jacket, which helps keep me dry at least until I've warmed up. A pair of gloves and a fleece hat that would likely come off before the end would complete the gear.
For the cold, it's mostly a combination of Nike and adidas tech fabrics (there happen to be Nike and adidas outlets not too far from my home so most of my gear that I don't buy online from ads through this site are obtained from those outlets at good discounts). Some pairs of heavier pants I have are usually good for me down to the 10-20 degree range, at which time I will add a pair of tights under them. I have some windpants for the severe cold. For the top, layering of tech fabrics for their wicking ability against my skin, cotton (yes, I'm still “old school” with the cotton) for insulation in the middle, and my Nike windbreaker if it's windy. A good fleece hat will usually suffice for me in all but the most severe conditions, in which case I might layer hats, and gloves of varying thickness depending on the temps finish it off.
There are similar garments that can be found at discount stores like Target for even less than the major label gear. Also, being smart and utilitarian is not the sole provice of the “old school”. 😉