Winter biking every day can be expensive. I try to buy things that can be worn elsewhere, in case the purchase doesn't work out for biking. But the winter-specific stuff accumulated over 5 yrs, the costs look like this:

210 Winter tights 3 pairs (cycling specific) My co. awarded 1 pair for not driving @$60
$ 6 Wool socks 3 pairs
$90 Gaerne winter boots (cycling specific)
100 waterproof rain pants 2 pairs (1 homemade, one SP) SP pants are worn through in the seat
160 SP rain jacket (cycling specific)
100 Marmot ATV soft shell jacket
$34 Sweaters 3 used wool
$ 0 Hats 2 homemade, and rain liner for helmet
$ 0 Leg Gaiters 2 homemade with leftover fabric from rain pants
$ 0 Neck Gaiter already had it
$10 Wrap Gaitor
$32 Goatskin, and ski gloves 2 pairs
===
742 That's no set of chump change!!! About $148/year

Stuff I bought and wear elsewhere that failed because it was too hot, freezing, sweaty, or whatever, is not incuded. Let's not go there