Here are some ideas for some very cheap snow geese decoys.
1) First the Texas Rag: basically a white rag tied to a dowel. Quick and easy to set up and really cheap. I have heard of people contacting linen companies and getting their throw out towels for this purpose. I must mention that the geese will fly closer with a big spread, however, their needs to be some realism to the decoy spread. So a few traditional decoys mixed in will help. The snow geese are looking for the contrast at high altitudes and the white specks are all that is needed. Something to remember is that snows are more community feeders than Canada geese, therefore a large bunch is very common for them. Canada's tend to be much more aggressive and will chase snows away and sometimes feed in smaller quantities.

Dont forget to remove the label - they make great snow goose decoys!

3) If you are looking for a professional decoy that is pretty cheap - don't forget to look at the silosock decoys.  The simple design allows for a fast setup and take down.  In addition, it will give some very lifelike movement to your decoy spread.  Use in combination with your cheap free decoys and you can be successful without spending thousands.