You’re definitely going to want a second hand laptop if you’re spending 300 quid. Best bet is to look on eBay. Pick a GPU (off the top of my head, maybe a 970 or 1050) and search for those. Then check each result and start comparing. It’s a nightmare trying to see if the CPU is any good. I usually check it on passmark every time
I hope you used archival ink so it will last for generations