You have my prayers. My greyhound had seizures also and it was terrifying. We thought she had epilepsy but she didn't, it was an aneursym.
The cheapest medication for epilepsy is phenobarbital. Another pettalker has an epileptic dog and she gets her perscription filled at the local pharmacy, she says it is much cheaper. Shaianne was on a half a pill once a day. 100 pills were anout $20. american money of course.
Good luck and please let us know how she is doing.
My vet told me that purebred dogs are more prone to epilepsy. And it can come upon them anywhere from 5-6 mos to 4 years.