Most, if not all, of the models you collect are shipped to you. Further, shipping is expensive, up to about one third the price of the model. Most will ship from inside the US but many will also come from international vendors. They seemingly have access to a supply of models that are not available anywhere else. There should be no stigma to buying internationally. The only issues are that international shipping is even more expensive and it takes longer mostly due to customs delays on both ends.
My experience with shipping times are as follows. For 60 domestic purchases packages arrived an average of 6 days from placement of order. For 40 international purchases packages arrived an average of 16 days from date of order. This is dependent of course on which packaging services the vendors used. Regular postal mail takes far longer than one of the private shippers. Of those Federal Express stands out as the fastest and most reliable. Customs delays are shorter and prediction of delivery dates tend to be more accurate. Also very reliable is the ebay SpeedPak service. It hands off to the USPS for final delivery but international transit and customs clearance times are very good.
On one purchase from a vendor in the same county where I live it took 45 days to arrive using USPS expedited mail. On another from the United Kingdom to here it took 67 days from door to door.
The old Jay Leno joke applies here. "Back in the old west days of stagecoaches and the Pony Express it used to take four months to deliver a package from Chicago to Los Angeles. Today's technogically modern high speed transportation postal network can get it here in half that time."
These delays can cause problems with the ordering process. On ebay you have 30 days after the latest estimated package arrival date to open a case for that transaction in the event the package does not arrive. After that date you lose your buyer protection. Ebay will encourage a private settlement between you and the seller including a refund of the entire amount. If there is no voluntary agreement reached they will step in and enforce a resolution including getting your money back for you. If shipping takes longer then this process is up to you to initiate. In the two cases listed above I received a refund from the seller before the presumed to be lost, supposedly tracked, packages eventually arrived. The right thing to do in these cases, which I did of course, was to contact the sellers and arrange payment.
About those tracking numbers. I learned a few things during this process of assembling the collection.
It's fun to receive a package and when the truck arrives its exciting. It's frustrating however to anticipate a delivery in two boxes, #1 of 2 and #2 of 2 only to hear the doorbell and see only one box, #2 of 2. On this occasion I ran out to the Fed Ex truck which was about to leave and asked where the other box was. The driver answered that it's probably on this truck but he couldn't see it and couldn't take the time to look for it right now. He said he would be back after he had delivered a few more packages and mine would then be easier to find. Later he did return with my #1 of 2 box.