A Development Environment will be really handy for you.

You can set up a quick and free while in the free tier and out of free tier the only cost you face is the cost of storage, and you can cut down on that with changing to WebP over PNG or larger format and WebM over gifs and mp4's, using cloudfront you cache the content in S3, then produce a cloudfront endpoint for you to look at.

Or you can even cache files you want to be accessed often without having to use google drive or dropbox. This site itself has currently 3 buckets servicing it, 2 for www. and 1 currently for develop. for example, you can click Here for a file. This is something you can wget :).