The typical dues paid to the West Coast Studio Locals (including Animation Guild, Cinematographers Guild, Editors Guild, Art Directors Guild) are in the neighborhood of 1% of annual earnings.
The typical benefits package costs approximately 10% of annual earnings. Sometimes a little more, sometimes a little less. Studios pay $5 per hour plus 6% of earnings for Industry Health Coverage and Industry Pension Plan and Individual Account Plan. Contributions into other IATSE benefit funds are a little lower.
So, a return of $10 in benefits for a $1 investment. That sounds like a pretty good deal to me.