so Fedex go by that, but I think everything under 10 to 20lb will have a minimum charge of roughly $40, and only if you drop off/pick up on a Thursday or Friday.
To maximize the cost, stuff minimum of 20lb of things in the smallest box available.
What is your zip code, I can look up the closest drop off center for you, I always do drop off because you will have a receipt after you drop it off.