my stubborn friend wants to lease a ds from 1and1, totally convinced by their datacenter info on their site. I want to prove him that other provicers like sagonet and servermatrix can provide that and MORE at a better price.

I would suggest doing a search for reviews on both locations and them showing them to him.

ask him to give you the 3 main reasons for going that route and post them here. we will try to give you some ammo against it.