Thats a super addition Anthony well done mate. It looks in great nick too! 8)
With regards to Maulsters question in terms of rarity - it really does depend on the 3 pack in question. Using the POTF Yak face as a basis for comparison is an interesting one but doesnt necessarily work in this case.
In all honesty some of the 3 pack sets are not too hard to find and others are extremely difficult to find. Some, like the second series creature set and ESB second series Bespin set come up every now and then. Maybe four or five examples a year. Whereas some of the really tough sets like the Bespin Alliance Set I have never seen come up for public sale in 5 years.
Prices vary massively based on condition and scarcity like everything in this hobby. Ive seen sets sell for £300 but I also know of graded sets selling for $20,000-25,000.