DO has the right amount of RAM, CPU, and storage space needed to get applications off the ground which is its standard droplet pricing supporting both monthly or hourly basis i.e $5/mo or $0.0007/hr respectively. Also it has high memory droplet plan which offers larger amounts of RAM, ideal for databases and in-memory caching whose monthly plan starts from $120 and hourly plan starts from $0.18
AWS supports both windows and linux servers. A lot of service options, APIs are available.
Heroku is basically going to cost you at least twice what a VPS would cost.
For a powerful server you’re actually using, it’s easy to pay $250/mo for what Amazon might have delivered for $100/mo or Digital Ocean for $80/mo.