Good deals on each of the Friends 10 seasons.  Shipping is free on orders over $25.  If needed, use this Filler Tool to qualify for free shipping.  Note that getting all 10 seasons in this case will add up to $89.90 shipped, comparing to the Complete Series Set, which is usually about $134 or much more.

Here is a screenshot for your reference that includes all 10 seasons for the complete series.

This deal has expired as prices for all seasons have been raised.