Of course design needs time to bake in the oven. You can't grind out a website every two weeks. I normally design a page and then forget about it for at least a day so I can get a fresh look at it. Sometimes you stumble upon the right design the first time, sometimes you need to go through dozens of ideas. It's all very unpredictable.
For the application itself that is a different story. It is a tremendous amount of work designing a app from the ground up so we are talking 80-100k at least. (I did all the HTML + CSS as well) Took me about a year worth of weekends to get it where it is right now. Being a co-founder I also got to make a lot of decisions without any input so it makes things move a lot faster.