LDN can be expensive if you get it from a compounding pharmacy. Here are some quick notes on how to compound it yourself cheaply with bottled water, naltrexone 50mg tablets & a shot glass:
http://brettborders.net/how-to-make-your-own-low-dose-naltrexone-ldn/
http://brettborders.net/how-to-make-your-own-low-dose-naltrexone-ldn/