Shipping wise it was my fault. Took a good 4 weeks for a piece to get from US to Australia on an M2M sale. It was somewhat expensive piece so the buyer and myself were both sweating pretty good. No tracking, no nothing, it was the first piece I sold outside of US.....I was ready to give a refund when it showed up.
Then I recently used the same shipping place to send a piece to UK and once again no tracking for like 2 weeks. It finally left LA yesterday. This time I paid for USPS priority international and it is still taking forever. Needless to say I will never use that shipping store again. Problem was it was the weekend and I wanted to get it out. Been better off waiting until Monday and just going the post office...the buyer would have received it sooner.
For receiving, 4-5 weeks is the longest. Now on some modding work......I have waited months.