As has been mentioned, You can get them out there on the markets. but they aren't always cheap.
Sea law on Amazon is showing $41.50
Castles & Ruins $24.95
Emer II couldn't find
On Amazon I could find the RM2 Elemental companion for $13
Found the RMFRP Fire and Ice Elemental Companion on Ebay for $40 to $45
So really not much options out there to get physical copies...
We are a Dedicated Fan base, so the options are limited and the values, on the average, tend to be Above original MSRP.