IPhone 5 now, or 5S/6 later?

I had an iPhone 4S a couple of months ago, but there was a catastrophic failure and I had to get rid of it. I then got a new sim card to put into my ancient 3G, but recently bought my friend's white 16GB 3GS for 10 bucks. It could run IOS 5 with all of the apps and imessage; it felt like a brand new phone compared to the 3G. Only problem is that the ear speaker doesn't work so I can only have phone calls on speaker phone or with bluetooth in my car, and after a nice drop to the pavement, it now has a hole in the top right corner of the screen which sometimes paralyzes the right 8th of the screen to touch. Now after having the phone for a couple weeks, its age is becoming more and more apparent. Frequent crashes, slow running, the problems mentioned before, etc. Now I'm itching for a new phone. Fortunately my contract recently ended so I can buy one. My original plan was to wait for whatever new iPhone will inevitably come out within the next couple of months and buy that, but now that this phone is experiencing problems, I'm also debating just getting a 5 now and being content. Anyone have any advice for me? Also, I'm not really interested in Androids, only iPhones.

I think you should wait until the iPhone 5S or 6. Or, when the iPhone 5s comes out, you can get the iPhone 5 for cheaper. Plus, the new iPhones usually come out in the fall time

The 5S will look exactly the same as the 5 except the processor probably clocked to run a bit faster, A new GPU, Probably a 13mp camera and maybe slightly bigger battery and possibly NFC.
So don't hold your breath for anything new because Apple always just sticks a few new bits in the S version and tries to call it a new phone when the iPhone 5 isn't even as good as the 14 month old Galaxy S3 so the 5S will be horribly outdated when it's released.

At this point, wait for the 5S.