I stuck with my Asus mobo sound for quite a while – as you say, D1, it has improved a lot – but the Creative Sound Blaster Z I have now definitely puts out better quality sound. Possibly not so noticeable on low-end computer speakers, but fed through a decent hi-fi, the difference is clear. It also has nice, chunky, gold-plated sockets.
That Asus monitor seems to have jumped in price – I paid under £350 for mine. Still way beyond your budget though, Pinback. Have a look at iiyama, perhaps? I used iiyama for many years – good budget monitors. Actually, this one has pretty good specs (and FreeSync if you’re running an AMD card): https://iiyama.com/gb_en/products/g-master-gb2488hsu-b3/ Currently £230 on Amazon, I believe.
<chortles> I bought the EVGA SuperNOVA 850 P2, 80+ PLATINUM 850W. I like EVGA kit – been using their GPUs for years now. It’s for a new/old build for which I’ve now gathered nearly all of the components.
Only 24″ and 1920×1080, but it suits me fine. It’s a very nice display – Oolite at 144fps (G-Sync/DP) is silky-smooth! Again, no built-in speakers, but what Kal said is true. I run my sound off a soundcard into my hi-fi.