I was at a coin show this past weekend and there was a coin dealer there that had the 4-medal set. Seeing that set up close in person makes me agree with you that they are much better in person than in the stock pics that the US Mint provided on their order site.
The last official mintage that I could find was on the USMint.gov March 25, 2018 report that had the mintage at 55,191.
The 2017 American Liberty 4-silver medal set is still currently on sale for $199.95. The most recent mintage for the 4-medal set (as of 3-25-2018 USMint report) stands at 30,449. FWIW I did not buy the 4-medal set (yet). I am not in a rush to get it at the moment.