Your printer should have nothing to do with your bar code on your book, which is a digital file. Are you printing a book yourself? If so, you aren't likely getting a product that can be sold in a store anyway.
You do not need to buy bar codes, only the ISBN numbers. There are a dozen ways to generate a free bar code.
Here is one way for books:
Go to www.lightningsource.com
. Under the "File Creation" tab you'll see an option called "Cover template generator."
Since you're not actually creating a book at Lightning Source, it doesn't matter what trim size or color or all that. Just choose stuff. All you need to get right is the ISBN and the price (and check the "put price in bar code.")
Lightning Source will email you the template, and you can discard all of it except the bar code and use it on the back of your book. A bar code is a bar code. It can be generated by anything and still work.
Now, that will embed the price IN the bar code. If you want to have a price on the back of the book, you just add text above it like you would any other text on your cover.