Cathy, it won't be a 'Sky Blue' 6 inch, unless it's an EARLY Sky Blue - a very turquoise-y 'Mediterranean' sky! The FLC (Full Lead Crystal) Sky Blue ones were the later, footed swans which are all nominally 8 inches. These in FLC Sky Blue are very sought-after and are VERY (3 figures!) expensive!
However, if your 6 inch swan IS an early Sky Blue, please sell it .... to me!

:chky: (deadly serious, actually

) These are amongst the MOST rare, and I (and indeed any swan collector) would pay very well indeed for one!

The Sapphire 10 inch should fetch a reasonable price, as there are fewer of these around - far more 8 inch ones available. The 8 inch 'Bristol Blue' one will be the Whitefriars colour known as 'Sanctuary Blue' and should also fetch a very GOOD price, as they are also quite rare! And as for your flotilla of Arctic Blue ones, remember that if you have any 6 inch and 10 inch ones, they will be slightly more desirable than the 8 inch ones, because the large and small ones were discontinued earlier.
Hope this helps. Please feel free to contact me if you need any more info