RAM upgrade advice needed

Building a PC for my son right now. We picked up an ASUS Prime B450M-A and an Intel Core i5-8400. What’s the smartest move for RAM that won't break the bank? Looking for a total best buy here. Thinking maybe 2x8GB 3000MHz. Thanks for the help.

https://www.amazon.com/corsair-vengeance-lpX-ddr4-16gb/dp/B07V6G6N6D

https://www.bestbuy.com/site/crucial-memory-ddr4-16gb-2x8gb/5446154.html

Not sure why some shops claim a 2-year warranty.
This one says 5 years.

https://www.newegg.com/gskill-ddr4-16gb-2x8gb/p/N82E16820213523

This is top-tier RAM (it uses micron e-die, clocked at 3000MHz CL15)

https://www.amazon.com/crucial-16gb-k...product/250537

I’m not sure which GPU you’re planning to pair this with, but honestly, it won't matter much. No matter what you pick, you can easily get away with the cheapest 3000MHz CL16 kit on the market.

Thanks for the input, guys. We ended up grabbing some Corsair 👍

Hope you don't mind me jumping in here, but I've got a similar question.
I’m looking to upgrade my RAM. Right now, I'm running 2x4GB Crucial DDR3 1600 MHz Ballistix. My motherboard is an ASUS P8Z77-V LX2. I checked the manual—page 1.2.3 covers the RAM configuration. I'm torn between grabbing another 2x4GB kit or just going with a single 1x8GB stick. Looking at their recommendations for slot placement, they only mention using 1, 2, or 4 sticks; they don't say a word about three. Will three sticks even work? And if I do that, am I messing up the dual or quad-channel performance? Basically, should I stick to a 2x4GB setup or does it not matter.

Also, I'll probably look for used parts. Retail prices these days are just ridiculous. If anyone is selling some or has a solid link for something similar to what I currently have, let me know.
Thanks!