Season : 2010-11
Team : Swansea
Managed to get promotion via the playoffs (beating Cardiff 5-3 in extra-time) while the board expected a top half finish.
Season : 2010-11
Team : AFC Wimbledon
Promoted via the playoffs (beating Luton Town 3-1).
I'm not sure how much it costs in Football Manager, but stadiums would generally cost around the £13,000,000 mark (and that's for a small, 10,000 or so) seater stadium.