If less than $120/month would actually bankrupt you, then yes, you have to go for the absolute cheapest option available. Sure, your particular use case very much favours DO's pricing, but if that kind of money would bankrupt you, then you have such little money that it's irrelevant what anyone but the cheapest provider costs.
I didn't mention anything about how much bandwidth my site uses. I just pointed out you can serve > 1 TiB from a DO droplet for $5 (or 10 TiB from 10 droplets for $50, or 100 TiB for $500, and so on).
The main point is that S3 egress costs are substantial for bandwidth-intensive applications.
I may have been misled by 'tiny' - I wouldn't have characterised something that throws out multiple terabytes of data per month as 'tiny'.
I take your point, though this being said, it again comes down to use case. A couple of hundred dollars a month for bandwidth is nothing for a business above a certain size, but it's tons for personal use. Depending on your use case, it may be also far more effective to use S3 and simply pay the data bill, rather than architect a system distributed across a ton of droplets.
