What Nodscene said. Backup all unneccesary files to another drive (ISO's, media, etc). Run
Ccleaner and
Defraggler. If your data is still too large to fit the SSD that you want, uninstall some programs, then run defraggler again. Use Acronis or Intel's own software to clone the system partition to the SSD. Once this is done, check to ensure TRIM is enabled, disable all scheduled defragmentation (kills an SSD) and turn off drive indexing.
Finally, reinstall any programs/games you may have uninstalled. If you don't have any room left on the SSD, you can install them on your old HDD. I would choose programs that don't mind having a longer load time (as the programs on the SSD will load nearly instantaneously).
Also, SSD's are becoming surprisingly affordable these days.
Here is a 240GB Samsung 840 Series 250GB SSD for $189.99. Add tax and shipping, and you're just slightly over your $200 limit.