Lessons, as a beginner I was taking beginner groups through the local university twice a week for the first month, then it escalated. Through the roof. Okay, I got hooked big time.
All group lessons within and without the uni - 12 hours max (usually around 10 hours)
Social practice 5 hours.
Good quality group lessons will help enormously and cut down on costs. Someplaces focus on privates and the groups are for feelgood, not much on how to dance. Great for some so I'm not knocking it. Deends on why you want to dance.
After a year or so I started taking a private a week (1hr) with whatever partner I ended up with that week. Not a good idea, you really need a regular partner to optimise, either the instructor themselves or an amateur.
Once I hit this country I started more privates up to three a week. I do know some people who are taking up to 15 a week (cost for them is around $100CAN per hour, they have a really good salesman as their instructor, top flight instruction in Toronto costs around $60-$70CAN per hour/55min).
Nowadays I am between main jobs so I am teaching dance, dancehosting and temping and tutoring and labouring and doing anything I can to earn a living. So I am now learning mainly from video and using my brain a great deal (why does that work, how can I get that to work etc.). I still socially dance around 12 hours a week on top of the rest of it all.
It's good for the sole and the soul (body and spirit).
D-spot.
Rule of thumb 1 hour private to 4 hours practice to get the greatest bang for your buck IF it is dancing you are wanting.