The Kansas Cosmosphere and Space Center is in my town, so I thought I would offer my services to you guys to get the stuff they have in their store, http://www.cosmospherestore.com
I will Charge you 5% more than the items price with sales tax, currently its 8.05% per dollar in my city
but that covers shipping and my convenience fee(packaging material, gas, personal time, ....).
so for example, this rocket http://www.cosmospherestore.com/autographed-saturn-v-rocket-model.html
is $600, with sales tax it would be $648.30 + 5% = 680.72
just a rough example but you get the idea
If you have any questions or want to place an order, lmk here or via pm