Kingston HyperX has a weekend sale on DDR4-3200 and DDR4-2666 Impact series memory kits for laptops. This sale can be combined with Amex shop small offer for an extra $5 cash back (see below* for details)
This is a premium line of memory, which is currently cheaper than even all generic brands of DDR4-2666 SODIMM available on the market.
16GB (2x8GB) DDR4-3200 $74.99
16GB (2x8GB) DDR4-2666 $52.99
32GB (2x16GB) DDR4-3200 $144.99
32GB (2x16GB) DDR4-2666 $101.99
64GB (2x32GB) DDR4-3200 $279.99
64GB (2x32GB) DDR4-2666 $197.99
DDR4-2933 is also on sale, with comparable prices.
Shipping is free.
*If you use an eligible Amex credit card to pay at Kingston.com, you can get an extra $5 cash back as part of "shop small business" program. Note that you may need to add the shop small offer to your card before shopping.
Impact series has pretty good timing (low latency) and supports intel XMP
Sample spec sheet [kingston.com]
Kingston is also selling some other parts and accessories upto %50 off in their weekend sale: