How much does a cat 5 cable cost?

It depends on a few different factors - first of all, you need to know the copper content. If it is pure copper it's going to be a lot more expensive than if it is 20% copper. Cheaper yet is an all steel cable, but they have a really bad track record and I wouldn't recommend them.

Also, if it is already terminated (has the heads on it) will determine how much it costs. If you get a long bulk cable without any heads it will be cheaper per foot, but will require some work on your part.

The shipping method is also a big factor in the price of cat 5 cable - make sure before you buy something that it is really the cheapest price - sometimes as much as 30% of the price of a cat5 cable can go to shipping!

For a rough guideline, you should be able to get a decent cat 5 cable that is 10' long for under $5. You should be able to get around 1000' (in a bulk spool) for around $55.