Meaning of some sentences

[zoobinshid]

Hello my dear masters,
Would you please tell me the meaning of these terms?Are they common?a better way to say the same thing?

1)she came upon somethig.
2)They'll get a buzz out of it.
3)going going gone.
4)we are just about done.
5)Bring my pizza and step on it.
6)You're both right on the money.
7)steady on!

Thanks in advance,

[Tdol]

1)she came upon somethig.- found by chance
2)They'll get a buzz out of it.- enjoy, find it exciting
3)going going gone.- used in auctions to close a sale- so 'going' means you still have a chance, 'gone' means the opportunity has passed
4)we are just about done.- nearly finished
5)Bring my pizza and step on it.- be quick
6)You're both right on the money. - correct
7)steady on!- calm down