Does anyone have an educated guess as to a future value of this coin say, 5 years out? Also, is $220 a good buy for this beautiful coin?
Future value, no idea. In the UK the PR-70/First Strike designation is generally ignored. $220 is almost certainly too expensive, as you can buy it in a presentation case from the Royal Mint for half the price, unless you care about the difference between a 69 and a 70.
I live in the USA, and many americans collect the Britannia and value the PR-70/First Strike designation. Buying the coin from the Royal Mint does not provide you with a certifiable coin, which is what most buyers want. I have watched the very coin I have purchased on ebay and time and time again the winning bid is over 200.00, so I don't believe I have paid too much. If you don't have any idea... don't post your comment. If you have an educated speculative guess, please do!
I do not have any idea what they would go for, I bought a Brittania/ASE set for 45 bucks a few years back. with the price of silver and the mints prices I would expect to see them for about 140 now, but I would not pay too large of a premium over spot for them, unless I heard a lot about them, saw the design and loved it, and I had not seen one anywhere else.
\ IMHO, the First Strike designation is a gimmick and these slabs are seriously overvalued. I'd rather have the coin in the original presentation case than certified, but it's entirely a matter of personal taste. Just my two cents.