Not necessarily true. From looking at many people's gear list I have found that those with extremly heavy packs not only have heavy gear, but they also bring far too much of it. So the cheapest way that you can lighten up your pack, is by leaving uncessary and redunant items at home. The cost of not bringing an item = $0.

For other items, there are lots of cheap alternatives. Why don't you post your gear list and tell us where you are going, how long for and your expected weather conditions and we would be happy to help chip at your pack.

As for a good read, take a look at Mark Verber's website:
http://www.verber.com/mark/outdoors/gear/index.html