Why not? If Kakashi has a reputation out there, has captured lots of big name villains, has hampered plots against the people in the Fire country, it would make sense he could earn a bounty just to get rid of him. If you are special, you can't be easily replaced and thus it's worth it to get rid of you individually. In the real world a war rarely misses one man but in the Naruto world losing Kakashi would be a significant blow to Konoha.

Just because you were a member of some old dusty group not anymore even existent shouldn't give you much of a bounty. However, if that group was something special and did something special that still matters, it's another story. Having a bounty also assumes there's somebody interested in paying the money, and that usually requires somebody benefits from the death.