Japanese wedding gift

I have a wedding to go to this wkend for two Japanese friends. I actually introduced them to each other. I know I should pay the 30,000 gift money to them but actually I can't afford it now, due to some unexpected car trouble. I can maybe afford 10,000 or a present. I'm really worries about what I should do. I don't want to cancel but I also want to give a gift, but money is really tight suddenly. Is there anything I can do without seeming rude?

Is your friend close to you?? if so you'd better to tell her about your situation and your worried. She whould say "Don't worry about the money/present" and you can go to their wedding comfortably. if I were her I am glad you congratulate me and it's doesn't matter about money/present!! Money thing is just a custom, so 10000 is fine. Enjoy the wedding!!