I really like them too. I purchased a PGC SP69 - it is a very pretty coin. :O)
If you don't think you'll ever want a slabbed coin, then I agree that buying an original unopened set would be the best deal.
I figured that since getting a nice coin slabbed would cost me about $30, I might as well purchase a slabbed SP69.
I've been tracking the
ebay auction prices on SP69 coins for a little while (coins only, not including the $1 bill). The prices for PCGS and NGC slabbed coins are similar for SP69.
From 29 June 2016 to 06 August 2016 there have been thirty-six SP69 auction sales with the average price of $29, including postage. There have been six BIN (Buy It Now) sales in the same time period, with an average price of $41.
For SP70, you'll pay around $80 for an NGC-slabbed coin, and around $170 for a PCGS-slabbed coin. Those are eyeball estimates.
~ Mark
Geek Section:eBay Auction Sales - 2016-S Native American dollar SP69 (coin only)Frequency = 36
Mean = $28.96
Median = $29.03
Mode = $ 31.00
Standard deviation = $3.69 (although it's probably not a normal distribution)
16th percentile = $25.27
84th percentile = $32.65
Polynomial trend line suggests price is relatively level at around the mean and median =/~ $29
y = 0.0135x2 - 0.6273x + 34.472
Rē = 0.2536