Help on picking a new hard drive for old DELL Inspirion 15 (3521 /5521)

old one Seagate Momentus thin 500gb. Now looking to replace and too many options , with the newbee concern of fit and function.
Recommendations for about the same hdd - from who, what and where - and LOW Price points would be nice.
thanks in advance

Despite the recent increase in prices for SSDs, I'd get whichever capacity, name brand SSD that fits within the budget, even if it's a USED SSD. Actually a used one would be exactly what I'd put in - I'd upgrade the SSD in another system and have a leftover to reuse. No way would I ever put a mechanical HDD in anything.

I happen to have a circa 2001 Dell Inspiron 8100 running Win7, that came with an IDE HDD, and I swapped in a 240GB SATA SSD with a $4 IDE to SATA adapter card - shucked the case off the SSD so the half length PCB in it, plus the adapter card fit into the HDD bay. Even limited to 133MB/s, 133MB/s plus so much lower latency made a huge difference in responsiveness, but it helped that old boat anchor of a laptop even more because it was a bit light on memory so using the pagefile at times.

Not a great time to be buying drives or memory because AI needs are driving prices up, but it doesn't seem like that's going to change anytime soon, so it is what it is.

Your first decision needs to be whether to go with SSD or the legacy spinning HDD. It will cost a bit more per GB, but I think a SSD is very much worth the cost. Yeah, everybody conceptually accepts SSDs are faster, but many may not appreciate by how much. For a side-by-side illustration, see my video: "Demonstration of SSD Booting Speed vs HDD"

My video compares a M.2 SSD, which is a tad faster than the 2.5" SATA form factor you'll be looking for, but it still gives you a good idea of how a traditional HDD compares.

There are lots of different SSD form factors, but you want to look for one that is the same 2.5" form factor and is a drop-in replacement for a traditional laptop HDD.

FTR, my wife still uses a 3521, which I upgraded with a SSD a few years back. It still works well for her. She uses it mostly for zoom meetings, sonce the laptop has a camera while her desktop rig does not.

As for size, 250-500 GB should be enough if you're price conscious.

As for brand, I prefer to stick with the well-known brands like Samsung, Western Digital, Seagate, Kingston, or Sandisk. As a PC tech I used to buy lots of drives to upgrade clients' systems, but I've been retired for several years so my brand preferences may be old prejudices talking, so take that into consideration.

I'd stay away from the lesser known brands because there are a lot of fakes flooding the market these days. For the same reason, I also stick to reputable vendors like Newegg.com and "Sold by Amazon". Avoid the third-party resellers on Amazon, Newegg marketplace, eBay, and the like. It's just too easy to get scammed.

Thanks! . I think I'll stick with the older HDD format. I can make a pot of coffee while is booting, as I usually put it into into sleep mode, and maybe reboot once a week after running CCleaner and Malware scans and cleans. .
Sincerely appreciate the input.