What's a cheap rain jacket that will withstand heavy rain for 2 hours on bikes?

Probably not the cheapest but this works great for outdoors activities and an alternative to goretex stuff. Not sure if they have in store but you can check if there's BF deals. This material has worked great for me cycling outdoors. You can also check out cycling stores, they carry really light rain jackets for cycling that go for around $150-200

Lululemon

Columbia outdry ex. Much cheaper than goretex and depending on who you ask just as or more waterproof than goretex. It isn't pretty though since the waterproof membrane is on the outside so it can look like you are wearing a garage bag.

What about sub 100? what are my options?

Garbage bags

AccountID wrote: ↑ Is Goretex/specialized rain jacket really the only option for this?
Of the costly waterproof jackets I have had, water eventually seeps through after 0.5 ~ 1 hour anyway

I had seen duck/rubber material for shoes, but I am not sure if I really want to wear a jacket made of that material, it's gonna be a sweat bucket inside.

IME decades of experience NOTHING will keep you dry, cheap nor expensive, as you also create humidity from the inside, which you've probably experienced on a nice warm dry day with activity that creates body heat. GoreTex & that type of product is 99% marketing hype in terms of keeping you dry. These are ALL "sweat buckets". Yes it could keep rain out, but these "fabrics" breathe out SO SLOWLY & with such SMALL VOLUME that you will still end up being wet but from the inside. Do NOT drink the breathability Kool Aid marketing hype, they may help if you are standing still, but as mentioned, so will any waterproof fabric such as a garbage bag. Ask for any sales person to PROVE WITH EVIDENCE the breathability & rate of breathing out that they are trying to sell. The problem is how much you are expecting to move while being outdoors & so how much body moisture you create which simply cannot evaporate especially if the ambient humidity outside your waterproof jacket is 90-100% or rain. Water trying to get outside a barrier to keep you dry, will be slowed down to the extreme by the ambient humidity / rain, even if the voodoo of GoreTex etc., actually worked. So you still get wet.

On super wet days, don't go out if you want to stay dry, work out inside where you can sweat but not become hypothermic.

Google REI shop, got their raincoat a few years ago. Wery satisfied with it!

Invest the money and get a proper Gore-Tex jacket. When I started year-round cycling in 1995, I cheaped out and bought a $35 rubber raincoat, they type construction traffic flaggers use. It was awful. So I spent the $200 on a MEC Bernoulli jacket. It last 15 years of daily use whenever it rained, which in Vancouver is a LOT. Cost me $13/year averaged out. Cheap. After it wore out I replaced it with a $300 Gore-Tex cycling jacket from Taiga. Had it for 8 years now; still holding strong. Seriously, the proper clothing can make all the difference between being miserable and enjoying your rainy bike commute. I like to compare it to swimming. If you're going to swim 40 laps, you need a proper swimsuit. Wear your jeans instead and you're going to be miserable.