Newegg has sales all year long. And it is not really up to them when. It has more to do with market supply and demand. If Micron decides to flood the market with DDR4 and sell Newegg a million sticks at discount prices, Newegg will have a sale on DDR4 then. They are not going to wait until some arbitrary date on the calendar. Yeah, they might have "Forth of July" sale or "Veteran's Day" sale, but typically, the other retailers will have similar sales at the same time.
And while Newegg is certainly one of my favorite sources for parts, I never buy from one source only. Amazon, B&H, and TigerDirect often have prices (don't forget to factor in shipping) that beat Newegg. So do your homework.
I generally recommend you just save and build up your budget until you can buy everything all at once. Start doing your homework to see what is out there and what features you want in your next computer. Then when you are ready, shop around and buy.
BTW, a common mistake many make is they buy a part today, a motherboard for example. Then next month, the CPU, then the next month RAM, the next the graphics card, and so on. This is a bad practice! For one, it is not uncommon for makers to update and release new revisions of the same model number. These revised parts correct bugs or replace a component that had a high failure rate. You could have an older revision sitting in the box for month when you could have had the latest. Or, you could buy a graphics card and put it on the shelf for a couple months only to learn in the meantime, somebody put out a better card for less that you would rather have (this happens a lot).
Also, the warranty period starts with the invoice date. Your warranty could be 1/3 over before you even start your build. And in some cases, if the part is beyond 30 days old, you have to deal with the manufacturer instead of the retailer. If the device was sitting on your closet shelf for 3 months waiting for you to get all your parts in, and suddenly you discover it is dead, it becomes a real PITA - not to mention frustrating as now you have to wait even longer - and may get stuck with additional shipping charges too.
