Lol, Spartans. As in the citizen's faught purely as Hoplites. By 200 BC, there was barely 300 citizens. Helots and what not filled up "support" troop positions.
'Locky: As zarax said there is no way to have different recruitment times or costs, but it is possible to have different recruitment requirements in different areas. It would be possible to require the construction of a special building (like a military colony) for the recruitment of Spartans elsewhere. I'm not wild about the idea though. The Spartans never succeeded in transplanting their social system, and they tended to stay pretty close to home.
Making the Spartans inspirational is easy enough, but it would require changing the legionary eagle references to something more generic.
Zarax: Galatians sound fine to me, but it may be a while before I can do much modding. I'm moving to Boston in a month or so, and I'll be pretty busy between now and then."
yeah. I know, the Spartans tended to stay close to home. But making them inspirational, would be fair, other troops would think highly of them no doubt.