The sale is expected to end very soon. Avoid the appalling Core M3 SKU as this Core i5 SKU will provide immensely faster performance and with double the RAM for just $75 more.
https://www.notebookcheck.net/Microsoft-Surface-Pro-6-with-Core-i5-8-GB-RAM-and-128-GB-SSD-is-only-675-USD-right-now.422355.0.html