Here’s an idea of the cost on http://wholecouponinserts.com/:
No purchase limits
No processing fees
Coupons are not clipped
Located in Florida
They ship orders within 24 hours of order submitted. Orders made before 11:00 am are guaranteed to ship same day. Saturday shipping deadline is 10:00 am for Saturday shipping.
Shipping of a 10-pack as listed above would likely be around $3.00.
They provide the coupon inserts at no charge; you are paying for their time. The price of the inserts is for labor to collect and mail inserts. You are only paying for the labor involved not the inserts.