While I agree that the OP should learn CSS/HTML (assuming they don't already know it), I know that for myself, someone who has a very solid understanding of both, that I sometimes find myself saying "FUCK IT MAN, I JUST WANT TO CODE THE APP." When you have to know how to do everything, from concept to front end to back end to deployment, sometimes it's great to just pass off the simple things to someone else.

So I think if you find yourself being the wearer of every hat imaginable, so long as you know what's being done, there's no problem with outsourcing it. Invariably you'll need to make changes once it's returned to make it work with your back end system so you'll need the hacking knowledge anyways. But having the brunt of the slicing and dicing and coding done for you eliminates the potential for one more headache along the way...