If that's truly all that's stopping you, try out Middleman (http://middlemanapp.com/) or my own Draughtsman (https://github.com/stdbrouw/draughtsman). Taking two minutes to install an app hopefully does not constitute "wasting time futzing around with build systems" :-)

Also, I think your problem is very particular to front-end devs and designers-that-code. If you're already doing back-end in your framework of choice, adding CoffeeScript or any kind of precompilation into the mix is usually just a one-liner in a config file away.