I have my own little project I am creating using RoR, I plan it to have small-medium load.With no doubt I started with BDD and TDD (Cucumber and RSpec to be exact, but I am also experienced with TestUnit), I like it but since it's my own project and it's a somewhat startup - I am changing many things in it, many requirements, many ideas how things should work and look. So it becomes too much time-consuming to always code it using BDD and TDD, even if I cover only common cases.What should I do? Should I sacrifice BDD and TDD for productivity till I get to some point when I have a solid basis and it's time for production, and than I write tests?Should I write them right now but as minimal as possible? Should I only write RSpec and forget about Cucumber for now? Or maybe just TestUnit to test model for now since it's the most important and everything else can change?Thanks in advance!Update:I know all the pros of TDD and BDD, by no means it makes it easier to scale and bugfix application in future and save time, but maybe it's more reasonable in my situation to wait few weeks till I have at least some skeleton architecture of my app and than once I am sure with it I can cover it with tests to have a solid base? And than continue with TDD and do all the tests with TDD.   
Should I use TDD and BDD if my project is changing fast?
unit testing;tdd;ruby on rails;bdd;integration testing