Help in buying old Laptop (Lenovo Ideapad Y550p)

Hi,

I want to buy old laptop of mine friend of 2010 model

The specs are
Lenovo Ideapad Y550p (Core i7 quad core with Nvidia geforce with CUDA)
4GB RAM, 450 GB Harddisk.

The Laptop has been used for 4 years and the battery is giving few minutes
of backup only. Otherwise the laptop is in good condition

Can you guys help me in deciding the price of the lappy as iam willing to buy it.

Thanks in Advance,

tspshikari