Just to be clear, the $5 is a one time charge to be able submit extensions to their store, not a charge for users to download extensions. I think it's a good solution to help keep pure garbage from being uploaded... if you upload something, you think it's worth $5 (hopefully a trivial sum to you.) If you don't want to pay the fee, you can tell people to download your extension from your own page and manually install it. Uploading it to the store just helps people discover your extension and makes installing the extension a one click thing.