Well, if you have a friend and use theirs, then they'll get the credit for you signing up. If you use the full $97, then he won't actually get anything unless you refer people--then he'll get $5 each.
If money is your main concern, then $97 is probably the way to go. That's how you get the 1st year for $22.40. The more features you use, the less you save at time of sign-up.
Out of that $97, you can subtract the following amounts for adding features:
Unique IPs: $30 each
Free Domain Registrations: $15 each
Added Bandwidth: $9 per 10% increase
Added Diskspace: $9 per 10% increase
So a code can be created with any combo of cash & features, up to $97 total.
Save up to $96 at Dreamhost with ALMOST97 promo code (I get $1).
Or save $97 with THEFULL97.