On this MB (PRIME A30M-K ) can you explain to me why all the A12 processors I have used do NOT need a GPU, while, so far, NONE of the Ryzen processors I have tried ( including the latest Ryzen 3 3300X ) do not work without a GPU , and yes I have tried the G versions as well? I also have the newest version BIOS, 5603x64. Also I did order this GPU in the hopes of getting things to work --> NEW GeForce GTX 750 4GB OR GeForce GT 730 2GB VGA HDMI DVI PCI-E Video CardOK...several things here...
You're understanding of PC's with integrated graphics was true when the integrated GPU's were on the motherboard. They're all internal to the processor now for both Intel and AMD. That's something for you to learn and not expect it different.
You're right that a 5700G will limit an NVME SSD to PCIe gen. 3 but the performance of a SATA SSD will be unaffected. Gen 4 performance will not be noticeable compared to Gen 3, not even to SATA, except in synthetic benchmarks.
I posted a link to Newegg with their$200/less GPU's. Get one of the RX-550's or GTX 1050's. Many, if not all, of them are used and refurb's and ship from China. That's the state of the market right now: you've got to be prepared to spend upwards of $900 to get a decent modern card brand new. Maybe less if you spend time looking for one of the rare cards that pop up at MSRP and you have to act fast when you find it. Nobody's going to do that for you, so you have to be knowledgeable of the range of possible cards you'd be willing to accept.
The cheapest modern card worth gaming on would be an RX6600XT or RTX3060...any mfr, any card, whatever pops up that's cheap enough to swallow.
RX5700/XT's or RTX2070's are rare and probably as expensive even used; same with RX580/590 and GTX1070's. Since they're out of production you'll probably only find them them as used or refurbs also and even then priced well above $200. You have to take whatever you can find, you can't go shopping for a specific card.
Bottom line: a $200 dollar budget is laughable for a playable GPU...or would be if everyone wasn't crying. Also why a 5700G is such a desire-able processor as you get to play games on it with an iGPU that's far better than the NVME is degraded at gen 3.