diff --git a/tsa/howto/conference.mdwn b/tsa/howto/conference.mdwn
index 6642eed68bd143171dfdda5df92320864abf27ab..9f05b6a78967584d4349c80eeb852b64513aabf9 100644
--- a/tsa/howto/conference.mdwn
+++ b/tsa/howto/conference.mdwn
@@ -109,6 +109,14 @@ The actualy prices quoted from Hetzner but virtual servers would
 probably be hosted in our infrastructure which might or might not
 incur additional costs.
 
+Cost estimate summary:
+
+| Platform        | One time  | Monthly        | Other                               |
+| --------        | --------  | -------        | ----------------------------------- |
+| Mumble          | 20 hours  | €13            | 2h/person + 100$/person for headset |
+| Jitsi           | 74 hours  | €54 + 10 hours |                                     |
+| Big Blue Button | 156 hours | €54 + 8 hours  |                                     |
+
 ### Mumble
 
 Assumed configuration
@@ -122,7 +130,7 @@ One time costs:
  * initial setup: 4 hours
  * puppet programming: 6 hours
  * maintenance costs: near zero
- * **Total**: 10 hours
+ * **Total**: 10 hours doubled to 20 hours for safety
 
 Recurring costs: