Advice, please. I upgraded my 2 year old, boring laptop to Windows 8...

and it kind of rules. :) Now, I'm thinking of doing some upgrades.

I have a Lenovo u450p laptop that I got before I started grad school a little over 2 years ago and it's taken a few spills, cracked a corner of the base (fix it with duct tape?), and survived a coffee spill on the keyboard (I spilled it a year ago, but I just replaced the keyboard this week when I decided that I was going to keep this baby). It's not a powerhouse, but it runs MS Office perfectly and everything else with decent ease. However, there are occasions when it does lag (scrolling in applications like Chrome, IE, opening some applications, etc).

Specs-wise, it's not that impressive, but I'm considering an upgrade with an SSD if I can find a decent 256 GB one for under $200. Is that going to improve the responsiveness and performance if I'm still using a "Intel Core™ 2 Duo processor SU7300 1.30 Ghz with ultra low voltage, dual-core, 800MHz system bus, and 3MB L2 cache", and the HD is "320GB (5400 rpm)"? Or should I just save my money and live with what I have until I get enough money to buy a better laptop?

Thanks for any advice you may have.