I went back to see what the drug was that they put Pickles on - it is called Cyproheptadine. It is actually an antihistimine for humans but for cats it lowers testosterone and raises serotonin. Anyway, for Pickles, it has completely stopped not only the spraying, but his aggression in general. No more stalking his sister or pacing and crying.

Cyproheptadine is about $15 a month.
Amitriptyline (Elavil) is an antianxiety drug and runs $10 for three months. (old drug - inexpensive in tab form) I have no idea about the cost of the Ami ear cream.
Fluoxetine (Prozac) is anywhere from $30-over $100 a month depending on the generic or brand name and if they use the veterinarian formulary.
Clomipramine (Clomicalm) which is the same as Ananfranil for humans and this one is about $10-$15 a month but sounds like the one specific for territorial aggression in cats. I *think* it is approved for dogs but used "off-label" for cats.
These prices are based on best price of internet sources. As far as I can find out, all the Ami tablets and the drug Pickles takes are not available as a veterinary drug. Vet drugs are actually much more expensive and I have been told that they have to meet higher standards of approval.
This is all stuff I looked up when we were wondering what to do for Pickles - maybe it will save you some time.

PS - Devon was also worried about "drugging" her kitty - but except for the behavioral improvement - there have been no changes such as sleepiness, clumsiness, etc - things you might expect to see with a "calming" medication.