Would a used MBP has the same guts as a new W530?
Here's what I'd be looking at:
I7 3610 cpu
1600x900 display (would use a monitor at work)
Nvidia Quadro K1000m 2gb graphics
8gb ddr3 1600mhz RAM
500gb 7200rpm HDD
16gb mSATA SSCD
All of that would be $1250ish. I'd spend almost twice that on a new MBP.
'02 Mini Cooper #40HS, '13 Scion FR-S #40CS, '12 Ducati SF848