Well, I have to say when I started biking I thought all the clothes were ridiculous as well. I rode a Mt. Bike for years without all the gear. I will agree that the stuff is ridiculously expensive and quite frankly, UGLY!! All those bright colors!
But....
The more I ride the more I realize the convenience of it all. I know that I don't like having my girly bits rubbed raw, so I did get some bike shorts. I also realized that I didn't really need all that padding, just something free of seems that rub. So, I buy tri shorts, which are way cheaper and the Sugoi ones I have are nice and soft inside.
Then I realized how nice it would be to grab a quick snack without stopping my bike and became jealous of other riders jersey pockets. I still couldn't imagine wearing one of those horrible polyester jerseys however. One day I was in a bike store and they had a biking vest with a big rear pocket for $9.99. Can't beat that. Now I just wear that over my regular merino wool t-shirts.
I still don't buy all the fancy food. Most that I have tried just makes me nauseous anyway!!
Good luck finding what works for you.