Intel and price don't belong in the same sentence. If you want to save money you build with AMD, unfortunately that is not an option for you. Since you're running an i5 already I don't know that a CPU upgrade on a price level of any AMD CPU would do anything for you.
I don't know that a separate sound card is going to be much of an improvement. Back in the olden days the case would be different, but in the past five to ten years on board sound has gotten much better.
My advice would be to do the SSD upgrade, this will decrease your boot times. After you have done that see how your performance is and where your bottleneck when doing your rendering. Pull up Task Manager and switch to the Performance tab. This will show you if your CPU is being maxed out. If it is then a CPU upgrade is what you're going to need, but for your current price you're not going to see that much improvement. I know that Handbrake will max out all 12 of my CPUs when converting from a DVD to MP4, but that is by design.