Looking for used monitor

If you want a good 2nd screen, better to buy new. But if you just want any old 2nd screen, many second-hand thrift stores have older LCD monitors for sale dirt cheap.

You can try ordering from Bauer Systems. They have a whole bunch of Lenovo 24" eIPS 1920x1200, HAS, for $95 + tax + shipping. I've never ordered from them, but a few years back, when 16:10 were being phased out, there was a thread on RFD about a similar monitor at Bauer.
http://www.bauersystems.com/price-list.html

As was mentioned, Thrift Stores would be a good place. I volunteer at one in my city, and I try to keep at least 3 on the store shelves at all times. Granted, some of tiny 4:3 ratio VGA ones, but more often now we also get 16:10 VGA/DVI ones as well, and sometimes even HDMI

+1 for Bauer Systems mentioned above. Shipping to Toronto is usually about $20 but you can arrange to pick up in Burlington.