If you're using a SaaS in the cloud, you're already locked-in. I'm fine with that unless there are proprietary components not available elsewhere (or not compatible with alternatives).

If you look at the breakdown, you'll notice that I'm using AWS products that are mostly commoditized at this point: EC2 (virtual servers) + S3 (file storage) + RDS (hosted Postgres database) + Cloudfront (CDN). Nothing is precluding me from renting a few servers elsewhere, and migrating some/all my usage off of AWS. I have a bash script I use for server provisioning to make the transition even easier.

When bootstrapping a business on a shoestring budget, not worrying about your main cost center for 2 years is indeed a smart business idea.