One trip we decided to post home a parcel (large shoebox size) of some rather heavy items that we'd bought, because we were running very close to the weight limit on our cases. Used the post office in the Mall at Millenia and it cost about $12 for Priority Mail and the goods arrived home the same day we did. Given the weight, I thought that was pretty good value.
We would do it again if we had a similar situation, but usually we have enough capacity in the cases to take it home the normal route, so it's not like it's something we'd need to do every trip.