I think there's a fair bit getting lost in translation here. We understand the questions you're asking, and there is definitely information in the detailed specification that contradicts itself, but as none of us work for PCS, we couldn't give you an acceptable answer, it would just be guesswork.
Did you even look around the forum for steps on a clean install?
https://www.pcspecialist.co.uk/forums/threads/microsoft-365-not-opening-maybe-after-windows-11-update-and-files-crashing.98599/#post-754483
Post #5 in that thread above is what I used recently.
AMD are about to go live (1PM UK time) on YouTube to reveal their new GPU's. Made even more interesting after Nvidia have seemingly dropped the ball with their latest and greatest GPU's.
From the PCS Finance page:
"Be in permanent paid employment (over 16 hours per week), retired and receiving a pension or self-employed."
I'd argue with that budget, you won't need finance. You'll be able to buy a top-tier PC and a new monitor for that money. Believe me, you don't want to be...