UK diabetics, I'm thinking about getting a Freestyle Libre/Dexcom but paying for it myself - does anyone else do this?

Basically what the title says. As I'm on the pump I need to use my insight blood test to control insulin and input carbs but I wanna get the libre/Dexcom to get better control of my sugars - so I can't get the new test on NHS.

I can get a Dexcom for £160 (single sensor and a G5 transmitter) or 4 sensors and a G5 transmitter for £275) I'm not sure if this is a good offer? I'd really love some help when shopping!