Powerline or a new router?

Greetings,

I am facing a bit of a situation in my apartment. Let me be clear from the jump—drilling holes through walls is absolutely out of the question.

Here is the setup: I have fiber internet coming in, currently running through a Netgear Nighthawk router. My speeds hit about 250 Mbps, so I’ve hardwired my desktop via LAN. I also work on a laptop at the same desk—though, since I haven't picked up a switch yet, I find myself constantly swapping the cable back and forth depending on what I need to do... quite inefficient.

Naturally, I intend to grab a 1Gbps switch soon, but there is a new complication: I just got a TV for the other room. Right now, the speed over Wi-Fi is hovering around 20 Mbps—which is pathetic, especially when I'm trying to stream 4K content on that TV.

So, what should I do? Should I invest in a high-end router that supports 5GHz? (The current one is stuck on b/g/n settings, and even if I try to push the bandwidth to 40MHz, the speed remains abysmal.) Or would it be smarter to go with Powerline adapters combined with a switch for my desk setup?

If I go the router route, I wouldn't need the extra switch, nor would I have to worry about whether the Powerline adapters actually work. To be honest, the electrical wiring in this place is incredibly temperamental—we deal with strange surges all the time. For instance, standard halogen bulbs here seem to blow out every two weeks—I finally swapped them for LEDs, thank god—but sometimes, just turning on my computer will trip a circuit breaker... things like that.

My main concern, however, is whether a better router could actually deliver decent speeds. It's roughly 30 feet away from the other room, but there are bathroom walls in the way—lots of tile involved.

Here is the layout:
View on imgur

I am also looking for equipment recommendations. I am strictly looking for the best bang for my buck—quality performance without unnecessary overkill.

I ended up using a powerline adapter to get my parents online in their house. We actually share the same electric meter—don't ask why, but when you're renovating an old place in the suburbs, you end up making all sorts of compromises—and the connection works perfectly for them. Even though our houses are about 30 feet apart, my setup is brand new while theirs is basically thirty years old. Everything runs smoothly, so I’d definitely suggest looking into powerline if you're dealing with a similar situation.

I don't have fiber optic, but since my speeds hit around 50 Mbps, it carries over to them just fine.

Does it matter if my powerline adapters are on the same circuit, or do they actually need to be on the exact same wire? Right now, I’ve got one outlet where my router is plugged in, which also runs through a splitter for the phone line, and then I have another outlet in the basement where I'm going to need internet access. I haven't a clue if I could just plug in a router or some other device down there to get a connection. Honestly, I'm pretty skeptical about those Wi-Fi extenders being any kind of real solution.

"Outlet"... wait, are you talking about a phone jack or a standard 120V wall socket?

Basically, you plug one Powerline adapter into a 120V outlet near your router, then just hit the router with an Ethernet cable from one of its LAN ports.
Then, you take the second adapter, plug it into a 120V outlet down in the basement, and run a LAN cable straight to your PC. It works best if they're on the same electrical phase and the same meter, though sometimes they'll still talk to each other even if they aren't—so it's worth checking first.

I was thinking about some kind of relay or something, though I can't quite put my finger on the technical term.
The reason I'm asking is because someone told me everything has to be on the same circuit, and now I'm just confused. Obviously, there's only one meter for the whole house. I was wondering if I could just buy a router and somehow wire it down into the basement since the connection is already there, but I have no idea if that's even doable.

If you're running powerline adapters, sometimes they only play nice if they're plugged into the same phase—especially if you've got a three-phase setup at your place. Other times, they work just fine even on different phases, so I figured it was worth a shot to test it out.

Also, take a look at the phone jack by your router. If there are extra wires tucked in there, check if you can run those four wires all the way down to the phone jack by your PC. If you can, you could basically wire them up to act like a 10/100Mbps LAN cable. If you need WiFi down there too, you could just hook up an old router in AP mode to that connection.

I don't have three-phase power. I can see electricity coming from one meter, but I have no clue if the outlets in my basement and upstairs are actually on the same circuit. Here’s a shot of the outlet up here. I was thinking about maybe grabbing this AP kit to see if that fixes the issue

So, does this phone jack I’ve got sitting in my basement (where the old landline and router used to be) actually work for anything anymore?

If you don't have three-phase power at your place, then honestly, any standard 120V outlet is fair game for those powerline adapters to work (you mentioned before that there was only one meter anyway).