Help me decide please

[Indominus-Rex]

Ok so i bought this 144hz monitor for $125 not even knowing what i was gonna do with it just because it was on sale at a pretty good price for my future pc build. But now I'm thinking if i should sell it for $150 (still lesser than market price) and just stick to using my 4k tv and a shitty 24 inch 1080p monitor I got from a sale too (though it was a killer deal at only $62 in my country at least) just for the sake of getting better pc parts since the one I'm building is subpar with average components. Is it a good idea? Or a totally dumb one? State your reasons.

 

Ryzen 2600

Asrock b350 pro4

Thermaltake versa j21

Corsair VS550

1tb wd hdd

8gb ddr4 2400mhz

GTX 2060/1160 (When it comes out)

 

Parts that I would like to upgrade; additional 8gb, get an SSD and possibly a better cpu/mobo