Obviously you've been away from pricing for a while. 3 TB drive = ~$100-120. 120 GB ssd = ~$60-70.
I'd actually much rather have a 240 GB SSD over a 3 TB drive.
120gb SSD = $54 http://www.amazon.com/Kingston-Digital-2-5-Inch-SV300S37A-120G/dp/B00A1ZTZOG/ref=sr_1_1?ie=UTF8&qid=1406284465&sr=8-1&keywords=120gb+ssd
3TB HDD = 107$ http://www.amazon.com/Western-Digital-Caviar-Green-Desktop/dp/B004RORMF6/ref=sr_1_3?ie=UTF8&qid=1406284454&sr=8-3&keywords=3TB
At least when you're comparing products compare ones in the right price range.
240gb SSD is enough for your main drive (way more than what you actually need).
That WD 3 TB drive would be absolute shit to use as a drive. 5400 RPM. It'll take a week to boot your computer with that after everything is loaded.
Also, we didn't even calculate power usage. Less than 1 watt for an SSD vs 10 watts for an hdd. Easily 10x the electricity usage!