As said elsewhere, being registered and being party member is different -- the latter involves much more commitment and participation.

I have no clue what's "typical". But I did look up some figures for you.

• Hungary, MSzP: minimum 100 Ft/month ($0.5), party members pay more on their own
  
• Hungary, Fidesz: 500 Ft/month ($2.5)
  
• Germany, SPD: the lowest price is €2.5 for students and low-income people, for normal party members, €5 to €245 minimum (increasing as function of income)
  
• Germany, Greens: 1% of netto income or more

_{*Lunatic*, n.
One whose delusions are out of fashion.}