Why replace gear when it stops being waterproof?
I regularly treat my bike gear with techwash and direct x reproofer, and will keep using a jacket until even that isn't enough to keep it waterproof, but I usually find that after about 18 months of daily use in all weathers and seasons my bike gear needs to be replaced (I do keep it as spares for a while after though so I can wash & reproof the new stuff), with 2 sets of kit to replace on an 18-month to 2 yearly basis I look out for the bargains, trousers at £30 a pair, £50 end of season jackets, My son's helmet and boots have to be replaced more frequently too as he is still growing, my helmet I try to replace about every 4-5 years, sooner if it starts to go baggy, I've never before had to replace a helmet because it has been used for the purpose it was designed for
I know people who are still using 15, 20 year old bike gear, that scares me, even leather goes brittle after a while and loses its protective qualities, but its the wearer's choice.
Crashy McDoof