The Pinecil goes in and out of stock on the pine64.com constantly, every batch is just sold out very quickly as people seem to love that device. For example right now at the time of my reply it is currently in stock.
Regarding the price gap: Mind that the Pine store is selling many devices at production cost or loss, while commercial stores have to calculate in a lot more costs, including calculatory entrepreneurs' salary and risks. The pine64.com store also sells from China, so you have to take taxes and import fees into account as well. The taxes are calculated from the device prices plus the shipping costs and they add up quickly.
Example with the reseller you linked (shipping to Germany):
Reseller: 56.36 USD + 7.52 USD shipping = 63.88 USD
pine64.com: 25.99 USD + 11.99 USD shipping + 7.22 USD taxes (plus fee from the shipping company for the import, roughly 6.50 USD) = 45.20 USD / 51.70 USD
So in this example it's slightly more expensive to buy from the reseller, however you will have a proper EU warranty and returning and repair would be considerably easier as well, plus the fast shipping compared to slow China shipping.
Regarding the price gap: Mind that the Pine store is selling many devices at production cost or loss, while commercial stores have to calculate in a lot more costs, including calculatory entrepreneurs' salary and risks. The pine64.com store also sells from China, so you have to take taxes and import fees into account as well. The taxes are calculated from the device prices plus the shipping costs and they add up quickly.
Example with the reseller you linked (shipping to Germany):
Reseller: 56.36 USD + 7.52 USD shipping = 63.88 USD
pine64.com: 25.99 USD + 11.99 USD shipping + 7.22 USD taxes (plus fee from the shipping company for the import, roughly 6.50 USD) = 45.20 USD / 51.70 USD
So in this example it's slightly more expensive to buy from the reseller, however you will have a proper EU warranty and returning and repair would be considerably easier as well, plus the fast shipping compared to slow China shipping.