Many computer vendors have outlet sites, where you can buy cheaper laptops that are unused. And they often have intermittent sales, so worth waiting to see if prices drop even more.
E.g. http://outlet.lenovo.com/
Alternatively, Thinkpad laptops specifically are pretty well built, and easy to replace parts. They have a downloadable manual on how to do so even! So you can just buy one off ebay for $150 and it'll probably work just fine, and worst case you can replace the hard drive.
This is specifically Thinkpad; generic Lenovo consumer laptops are likely not designed for maintenance.