Updating DBaaS flavours and price (#1691)

* Update possible DBaaS prices

* Added some comments about backup costs

---------

Co-authored-by: Rasmus Kronberg <43936697+rkronberg@users.noreply.github.com>
Co-authored-by: Joonas Somero <50655931+joonas-somero@users.noreply.github.com>

Author: 3 people

docs/cloud/dbaas/flavors.md

@@ -12,20 +12,26 @@ The database instances are hosted on top of cPouta. The billing is based on the
 
 ## Flavor types
 
-| Flavor | Cores|Memory<br/>(GiB) | Billing<br/>Units<br/>/h |
+| Flavor | Cores | Memory (GiB) | Billing Units / hour |
 |--- |:---:|:---:|:---:|
-| standard.small   | 2 | 2   | 4 |
-| standard.medium  | 3 | 4   | 7 |
-| standard.large   | 4 | 7   | 11 |
-| standard.xlarge  | 6 | 15  | 21 |
-| standard.xxlarge | 8 | 30  | 38 |
-| standard.3xlarge | 8 | 60  | 68 |
-| hpc.5.16core    | 16 | 55  | 61 |
+| standard.small   | 2 | 1.9  | 2 |
+| standard.medium  | 3 | 3.9 | 4 |
+| standard.large   | 4 | 7.8 | 7 |
+| standard.xlarge  | 6 | 15  | 13 |
+| standard.xxlarge | 8 | 31  | 25 |
+| standard.3xlarge | 8 | 62  | 50 |
+| hpc.5.16core    | 16 | 58  | 60 |
+<!-- should this flavor exist here: | hpc.6.32core    | 32 | 116 | 120 | -->
 <!--- We should probably remove standard.3xlarge in favor of supporting hpc.5.16core -->
 
 ## Other resources
 
-| Resource type | Unit | Billing<br/>Units<br/>/h |
-|--- |--- |--- |
-| Volumes | GiB reserved | 0.1 BU/GiB |
-| Backups | GiB usage | 0.1 BU/GiB |
+| Resource type | Unit | Billing Units / GiB hour |
+|--- |:---:|:---:|
+| Volumes | GiB reserved | 0.01 |
+| Backups | GiB usage | 0.003 |
+
+Note that backups are taken automatically once a day and are stored for 90 days. This means that
+after 90 days you will have consistently 90 backups per instance. This means that each backup
+will in practice cost 6.48 Billing Units / GiB. Another way of thinking about it is that having
+backups costs 0.27 BU per hour if your average backup size is 1 GiB.