The Excalibur is supposed to be the best. I have a cheap Ronco dehydrator and it works well enough but I guess there are fancy things you can do with the kind that has a fan that I can't do with my cheap dehydrator.
I have decided that it is not possible to save money on some foods. For instance, dehydrated bananas require you to purchase a huge bunch of bananas and what you end up with is a snack that is so tasty you eat more bananas in a sitting than you might if they were fresh!
I think a good way to save some real money would be if you have access to backyard fruit. There is an apple tree on my walk to work that drops all its fruit every year. I intend to pick up a few apples on my way home from work each day when the apples are falling. I could dehydrate those. Same for a plum tree also on my way home from work. It is legal to take other people's fruit if it hangs over into public property, so I do not worry about the legality of this.
I have learned that it's a good idea never to leave the house without a plastic bag or two. You never know what you might find.
A good resource for dehydrator recipes are backpacking recipe sites and raw foods recipe sites.