They are quick sessions, a limited number of pictures... sometimes photographers will set up, say, 6 to 8 sessions of 20 minutes each for an afternoon, have all the clients meet them at a specified location, and offer a small selection of pictures and a disk or some such. Honestly, I don't think they make much sense for film shooters, and if $150 is too much for your client, then you don't want them as a client.