hi luckyguy

30 min. for a first time visit will most likely feel a bit rushed and probably not allow enough time for the experience you would like to have. most any provider will undoubtedly try to spend at least the first few minutes engaged in light conversation trying to get to know a new client, which helps make both of you more comfortable, and leads to a much more enjoyable time all around.
but if all you can afford is the half hour, then a good provider would do her best to please, although that might be very limited due to the time.

best regards and play safe, mr.man