Simply put, you get what you pay for. If you have a low budget you probably won't be able to get a very skilled artist/musician/coder. Most low budget projects that do have above average production value tend to be done by a tight team of friends or a solo developer with sufficient know-how. Those scenarios usually don't involve a lot of money since they are all doing it out of their own pockets.
That said, if you want to hire people you'll probably need some money to spend if you want quality stuff, exclusive assets are generally much more expensive than the stuff you can buy on asset stores (but then your assets won't be unique, which is not optimal).
It's also usually a good idea to branch out into other trades as a designer (which I assume you are, given the info) as being solely a designer limits you significantly unless you can pay people to do stuff for you. Getting your hands dirty in coding or asset creation is usually a good thing to do because then you can do other stuff than just being the "ideas guy", that way you reduce cost and have more control.