If you want lessons, don't go to Arthur Murray they have a real bad name in ballroom dancing. If you want lessons, you can get group lessons from lots of places for about $10 a lesson. private lessons can run between $35 and $75 per hour lesson. If you guys want to find out more I will dig up specifics but you can also come to the USA Dance Ballroom Dance that happens every weekend and ask. They are doing Argentine Tango right now. It's $8 for nonmembers and the class lasts an hour. then the dance continues for another 3 hours.
If swing is your thing, Dallas Swing Dance Society does a dance saturdays with lessons I believe. They are similarly priced.
There are tons of places in town that do free Salsa lessons in town.
If you wanna learn to dance, I can hook ya up.