The best thing I bought that was cycling-specific was the log house designs rain cape, I found myself overheating in rainsuits but the cape's open bottom gives a nice cooling effect. I use galoshes to keep my feet dry. The rain cape came from campmor.com and the galoshes were sold locally and way cheaper than the cycling-specific booties, but they can get hot in summer, but I just wear sandals or crocs in the rainy heat.

I have some wool longjohns and they work really well as a baselayer or by themselves as tights in moderately cool weather. I like any expensive stuff I buy to be multi-use. I have had good experience using a wool sweather (thrift shop style) underneath a windbreaker for the early winter when mornings are cold but the days can get warm. I bought a cycling windbreaker 'cos I had a big ass crack problem and it was pretty cheap.

In the winter months I wear large winter boots that come up near the knee.. I never get cold or wet feet. BMX pedals are great too, they keep the feet planted and allow the use of a wide range of shoes. If it's slushy out in the winter I just have a cheap pair of slush/splash pants to keep me dry. My winter coat is a heavy construction coat so it's high-vis but they're really expensive if you have to buy them, I got mine from an employer.

I do love my bike shorts for anything over 20 or 30km, but they are nice to have all the time if you can change easily enough at work. I don't put them on when I'm on short or social rides though.