If you have access to someone technically savvy, I'd encourage you to revisit trying to get Windows 10 on your current machine before making a new computer purchase if you're looking to be frugal. I waited until the last minute with both an elderly Toshiba laptop and a Dell refurbished desktop because I'm not a Windows 10 fan. Both machines are around 10 years old. While not blazing fast, they work fine and I wasn't in a hurry to replace them. DH was able to get both machines updated after getting off to a bit of a rocky start. A family member with an even older desktop was able to get Windows 10 installed and humming along like a charm, although it required a lot more work and far more patience and computer savvy than I possess. ZDNet.com had some articles on updating to Windows 10 that DH found helpful.
I was going to go to Linux Mint if I couldn't get Windows 10 on my machines (article on Mint also on ZDNet.com). However, you may occasionally encounter something that won't work correctly with Linux.
If you have to purchase, I don't know if you have a computer store like Microcenter in your area. I thought of Microcenter because they have brick and mortar stores where you could go in person, as well as selling on-line, and they have refurbished computers which can save you a bunch of money. Other entities such as Best Buy, Staples, Newegg, etc., also sell refurbs. Both of our home desktops are refurbs and they've worked fine. Since so many companies lease computers from Dell versus buying, there are many newly off-lease Dell refurbs out there. My current and two previous work laptops (employer owned) were Dell and I had no problems with any of them. After saving so much money purchasing refurbs last time around and being happy with the machines, I don't know that I'd spring for a new computer at this point. A good retailer will provide a warranty on a refurbished machine, although it may be shorter than a manufacturer's warranty.
I also have a hand me down Surface and like it, although I must admit I use it more for streaming work-outs (YT plus several streaming services) through the TV in my bedroom than anything else. Best hand me down gift ever!