I bought a 200mw 5.8ghz transmitter/receiver, a clover antenna, a video out cable for gopro and a 4.3" monitor for $55 at banggood.com. you can get the transmitter/receiver on amazon for less than $40. Then all you need is vieo out cable for gopro, a battery and a monitor.
I wouldn't change much. Swap $75 power system for this sexy $130 power system. Drop the extra $30 on a higher quality receiver, larger battery, or many extra props, depending on what your needs are.
This build is actually going to get some cheapo FPV gear slapped onto it once I have it flying well enough. I snagged a $42 VTx/Rx combo at the same time. Still trying to work out what I'm going to do for a cheap camera and ground station display though.
That should get you going for about $100.00. Don't buy fatshark goggles on amazon unless you want to pay 100 extra. getfpv.com has fair prices and domestic shipping. If you really want to use amazon cards though, theres the fatshark predator v2 RTF kit.
Lastly, you really should get an amateur radio (ham) technician license. You aren't (legally) allowed to transmit without a license. EDIT: Unless of course the item is Part 15 approved, which is mostly 25mW little TX's that will not be good enough.