I bought a Taranis QX7 remote controller (~$100), which is amazing and I love it and you can use it with any other RC vehicle you want. I even hook up the receiver to my hardware projects so I can control them remotely.

You also need an FrSky XSR or R-XSR receiver (~$10), a Beitian BN-220 GPS (~$10), a motor and ESC (be careful, get a plane ESC, not a quad ESC, the plane one is larger and has better heat dissipation, ~$30). You need two small servos for the elevons, those cost about a dollar each. You also need a good soldering iron (the TS100 is $35 and is amazing.

For the controller, the Kakute F7 is fantastic and costs $45ish. It can fly in modes ranging from manual to completely autonomous (you get a Google Maps interface and mark where you want it to go and it just flies to those points). This may be a bit overkill, as it's the best board around, you can get a cheaper one (or maybe one that is made specifically for planes) no problem, but it's only $10 cheaper.

The FPV goggles can cost around $30 for some cheap ones, adjust those to taste.

I think that's it for components, although I should probably do a proper writeup if people are interested. There's much info out there already, but it might not be concentrated in one place. Let me know if you have any more questions!