Upgrade a MBP(8,1) dual i7 to 16GB RAM from 4GB or to a SSD? I currently find my new computer a bit slow when it comes to my number crunching requirements. Also, I find my computer painfully slow when it's running VirtualBox. 

My budget is around $500. Newegg has 2 x 8GB for ~$220 and the 256GB for around $500. 

My uses:


Heavy Number Crunching including calculations, multiple iterations, large matrix development and calculation (Not graphics)
Virtual Box with windows 7 for Visual Studio access and some other windows only GIS and Number Crunching software
General Internet Lamery
Word Processing (Microsoft Office)
16GB Memory + 128GB SSD + Data Doubler from OWC (or analog from ebay) to put SSD into it. Only caveat would be if your MBP is one of early ones that had Optical SATA connector capped at 3Gbps. Then if you want SSD to be as fast as possible it's better to put it in place of HDD.