Why do I need 3gb ram? Buy a box with physical antenna eg minix u9h, q10 pro, x92 etc to solve your problem

Whilst nice to have.. You do not need 3GB RAM for better UI & performance. Those come from the box's hardware + software combo. A poorly made box with 10GB RAM will NOT improve performance. In fact, performance will be worse off than on say a 2GB Box that's well specced and has an awesome software to boot. Think about it, we don't use these boxes like our phones. For example, TouchWiz software on a Samsung flagship like the  Note 8 takes up a lot of resources just on its own.. Cuz fancy features, graphics etc.. So even if it ships with 4GB RAM, the OS itself has to allocate sometimes up to or more than 50% RAM to keep it's head in the game. The remaining RAM is then used for your apps. We do not have or really need such flowery-ness? on our media boxes (at least most don't). We simply want it to boot up and play what we want with minimal fuss. Which means at most you'll be running one app in the foreground and a few in the background. Android's OS RAM management on a good box can be tweaked to keep the most important apps running and surrender the rest. So I'd concentrate more on getting a device as suggested that excels in the WiFi and performance department than rely on it having 3GB RAM.. So if this box you found does both well (as evident from real world reviews) and within your budget, sure go for it.

Edited for better clarity..