Have you considered Powergrips? My daily bike has a cheap setup of platforms w/powergrips that cost me about $35. That's a lot cheaper than clipless. While nothing is as good as clipless pedals and special shoes, these will greatly improve your performance and safety. They are easy to get in and out of (I ride in a lot of traffic w/lights) once you get used to them. Also, when you don't want to use the straps, you just stomp down on them and you hardly know they're there.
While a $20 bike and a $2000 bike will both get you from A to B, the money you spend is up to you. Spend as much as you want, but don't let your bike get stolen.