Freeomania
The inability to control yourself when items are available free. E.g. stealing unnecessary sauce packets from a fish and chip shop, because you can and never really be sure when a free tartare packet will be handy, even though you will probably throw them out the next time you clean your car. Same goes with jam packets from breakfast buffets.
Man, Amy suffers from chronic freeomania; even when she doesn't want to drink if the booze is free she knocks them back like the prohibition is imminent. (Please note: freeomania is a chronic illness and sufferers are particularly vulnerable at 21st's, weddings, farmers' markets and gallery openings).