There honestly is no such thing as a teacup pig. It's a load of bull and any breeder who advertises them as such, is not being 100% honest. Anything you read about 'restricting feed' to keep them from growing large is also a load of bull.
Sophia (my Pot belly) was completely feral when I got her from my cousins when she was 9 weeks old.. She was addorible, she's addorible now, but she is a handful!
When my pot belly lived inside she learned how to turn on the water - note she did NOT know how to turn it off so ran our well dry costing us $400+! She also learned how to get into our refrigerator, eating our groceries, costing us hundreds each month! She destroyed our linoleum in the kitchen.. again.. more money.
To spay her to keep her potty habits in check was $300. (You will need to spay/neuter your pig.)
IMO, pigs belong outside for at least a major part of the day.. and should be allowed to be pigs!! While I loved having Sophie inside and she enjoyed 24/7 food, it is not the life for a
pig!
www.pigs4ever.com is probably the best site you'll find.
Edited to add:
"As for the so-called Teacup or Micro Mini pig's, these are just normal potbellied pig's that have been chronically underfed and malnourished in an attempt to keep them small. Their life span is maybe FIVE YEARS. This is because the pig stays tiny, BUT THE ORGANS continue to GROW NORMAL SIZE for a normal size pig. Teacups, Micro-Mini's, European Bluebutts, these are all fancy names made up by breeders. All potbellied pigs within the United States come from the same line. "
^ Taken directly from Pigs4ever.com.