Using Oracle APEX for building application

Pricing

https://www.oracle.com/application-development/apex/faq/#:~:text=Oracle%20APEX%20Service%20is%20a,1%20TB%20of%20Exadata%20storage

https://www.oracle.com/cloud/price-list.html#apex

https://docs.oracle.com/en/cloud/paas/apex/gsadd/always-free-oracle-apex-application-development.html#GUID-0B0617FC-1E69-482A-9EFF-6E2D3F7EA0B5

Assuming instance is up 24 hours and 30 days in a month

0.3226 * 24 * 30 = 232.3 + 118.40  =   USD 350.70    

Assuming instance is up 10 hours and 30 days in a month

0.3226 * 10 * 30 = 96.80 + 118.40  =   USD215.2

Always free tier is 1 OCPU updo 20 GB can be used for dev and test environments

We can take any customer live without any cost until they reach 20 GB storage limit.

Application will be running with ATP 19c Enterprise Edition Database and APEX.

https://apex.oracle.com/en/

APEX Built in features

1. User management

2. Authentication support to third party