I've spotted a nice looking PC with monitor deal on ebay, what do people think of the spec: Dell OptiPlex 7020 PC Desktop, 500GB, Intel Core i5 4th Gen., 3.3GHz, 16GB. Win 10 Pro Needs an SSD, but worth about £200, right?
Then assuming you don't want to assemble your own machine, go with the AWD 3200G, and preferably upgrade to 16GB 3000MHz RAM which is £350. Put your own Windows on it. If you don't do that, at least take the 8GB 3000Mhz memory upgrade for the extra £7 which comes out at £317. This cost is negligible but helps to improve the graphics performance. Nobody's mind shall be blown in terms of performance or value or upgradeability, but it's also not terrible nor a rip off so you can be comfortable with the purchase. IMO the best bang per buck to really be had is to go up to about £460 and then you have a really nice machine.
I suppose i could install WIndows 7, i still have the CD.
Yes. You can also use Windows 7 & 8 keys on 10. They just need to match the edition,so 7 pro used on 10 pro,7 home used on 10 home,etc,etc. I am using my windows 7 pro key on windows 10 pro(download from Microsoft for free). https://www.microsoft.com/en-gb/software-download/windows10ISO
It's quite hard to try not to think about upgrading whish will almost be non existent due to the motherboard. But if it's older games and retro games then this will do the trick. The problem is once you start to load games that do not run very well you get addicted to making them run .So if you can I suggest pushing your budget as far as it can go and research,research, research before buying. I would suggest maybe going for a Ryzen 3 2200g as there will be plenty of cheap upgrades if you need them and you will not need a graphics card as the integrated graphics will easily handle older ( pre 2015?) Games ( lower settings for triple AAA demanding games). I myself am a massive cheapskate so am always looking for the next upgrade and I my go that route myself.