The regumate costs $238 I think - I get it from Valley Vet with a prescription. I can't remember the cost of the flush but believe it was under $200.
The flush was what I was talking about earlier, except my vet called it "infusion". Having it done one time didn't seem to do the trick with mine. It took 3 days in a row and I think it was about $30 a pop. They have to be in heat when you do it so the cervix will be open, otherwise you can damage the cervix and they'll never carry another foal again.