You should tell your client that using nofollow on his outbound links does not prevent PageRank bleed. That is old information that hasn’t been true for about two years. The link that confirms this from an official Google engineer and spokesman was already mentioned by shaktimaan.
Nofollow can no longer work to prevent PR from bleed. That said, PR bleed isn’t as much of a problem as most folks make it out to be. When you link-out you bleed PR but you also benefit from outbound links as well. It is a two-street, benefits in both directions.
The only reason to use the Nofollow attribute is when you cannot or don’t want to vouch for the website you are linking to. Let me repeat, using nofollow does not prevent the dilution of your PageRank power. And at no time does linking out reduce your own page’s PageRank, you PageRank has no value except in how it weights the importance of anchor text influence on pages you link to.