[citation][nom]Shadow703793[/nom]Umm.... no. Not even close.[/citation]
Obviously it will end up costing more if you're going to do a project like this and not use the containers again, because those are insanely expensive.
But the actual liquid nitrogen itself is extracted from liquified air extremely easily and is made industrially for very very little. You know the air we breathe is about 80% nitrogen right?
[EDIT: Here's a link to something,
http://hypertextbook.com/facts/2007/KarenFan.shtml , it seems the internet is a bit quiet on how much it costs. Also, some of the documents here, http://www.nmtc.net/search/liquid-nitrogen-tank-price, show that the price varies wildly depending on who you are, how much you are buying, and who you buy it from, from less than a cent per litre to around a dollar.... Still cheaper than milk though :-]. ]