Smaller stuff is no problem at all. Some of the bigger stuff is where the postage costs get really high. USPS will only ship packages with a max length of 60" and max girth of 108" with a max weight of 70 lbs., anything bigger you have to go to DHL, UPS, or FedEx. A 5lb. package costs about 23 quid to ship and a 70lb. package costs about 180 quid to ship via USPS/ParcelForce to give you an idea.