Mann-Up = $1 for a ticket.
Ticket = 1 time use.
No ty. :P.
If you play a mission but don't finish it, it doesn't use the ticket.
It only uses the ticket when you fully complete a mission.
So you could just buy a ticket, get on the servers faster than normal, and never complete the missions.
As for the drops, you just get random weapons, with a chance of getting the new hats.
You have to complete all 6 missions, which means 6 tickets, to be in with a chance of getting the Silver/Gold botkiller weapons.
Of which, the lowest price on the gold ones currently is 3-4 buds.
Regulars are around a buds or so.