I thought I would just post this to let people know... If it is a medium amount of plants (or if you just prefer a box or need the styrofoam lined box), the shipping is almost always as follows:
-$5.50 for priority mail (2 day) in a styrofoam lined box (only needed if your temperature for the week of shipping is below freezing)
-$5.30 for priority mail without styrofoam
-$2-3.65 for bubble mailers (big envelopes with bubble wrap lining)
NOTE: Shipping costs $5.14 but I have to factor in the cost of the bag and styrofoam