Lenovo ThinkPad T420 4236 - 14" - Core i7 2620M - 1600x900 - 4 GB RAM - 500 GB HDD
Price 1 263$
Lenovo ThinkPad T420 i5 2520, 4GB, 1366x768 , 160 GB (no SSD) HD
Price 853 $
The two of them are mint-condition, also the same warranty
Are the specs of the first one worth to spend 400$ more?
I would say that out of those two, yes it would be worth it to get the more expensive system. That is based on the screen alone, and not because of the hard drive or processor. Maybe you could find another one with specs like choice two but with the 1600x900.