Lexmark has a great offer now, you can send in 5 of their cartridges (free postage paid envelopes) and you will get one NEW one free
I already did this twice and got my ink (37xl $35.xx)
go to Lexmark sign up and request postage paid envelopes
BTW
.. I got a big box of old cartridges an ebay, since i do ink recycling at staples and office max too.