Amazon AWS RDS costs:
| Payment Option | Upfront | Hourly | Monthly* | Effective Hourly** | Effective Monthly | On-Demand |
|---|---|---|---|---|---|---|
| No Upfront | $0 | $.017 | $10.22 | $0.014 | $10.08 | $0.017 per Hour, $12.24/month |
| Partial Upfront | $51 | $.006 | $4.38 | $0.012 | $8.57 | |
| All Upfront | $102 | $.000 | $0.00 | $0.012 | $8.50 |
Some common things you might want to be able to do:
Change the size of a the storage after configuring the instance
Yes: http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ModifyInstance.MySQL.html