Most of online sellers would agree that the cost of storage of your digital files would probably be one of the highest and some hosting companies place restriction on the sites from hosting too many files. Don't worry, with my principle of being frugal, there are countless of free or cheap online cloud storage companies that you can use to host your files. Here are some of my favourite ones and tutorials on how to use them.
Dropbox - Click here to sign up for free account
Amazon S3 - First year free
Mediafire - Free account serve ads and might not be as professional for your customers
There are hundreds more company that I did not have a chance to mention in this post but feel free to do your research. One word of caution is that with many companies offering a freemium model, it is best to stick with the ones that have been around the block for a little bit longer.