Baby Carrier

Before I found out I'm expecting twins I set my heart on getting an ergobaby baby carrier.  But now I'm not sure if that makes sense.  Should I get one baby carrier, or two or none?  If we take them both out a stroller seems more convenient (we'll get a good stroller for sure).  How often would you just take one of the twins so it's worth getting a carrier?  What are your thoughts?