The Crucial MX500 has been my favourite budget SATA SSD for absolutely yonks, and right now you can pick up a 250GB model for an all-time low of just £30 over at Amazon. That's even lower than it was a couple of weeks ago, and an absolutely stonking SSD deal if ever I saw one. If you're looking to pick up a SATA SSD on the cheap, it doesn't get any better than this.
Alas, only the 250GB model seems to enjoying this kind of discount right now, as the 500GB model is still a very average £53 at time of writing, having risen from £48 back in mid-September. The 1TB model is still a decent buy at £96, though, its price having remained pretty steady over the last few months, but really, you're much better off buying the similarly priced WD Blue SN550 for this kind of money if your motherboard supports NVMe SSDs. This is back down to its all-time low of £95 right now and will deliver much faster speeds than the SATA-based MX500.
As for the 2TB version of the Crucial MX500, this is much more expensive than normal right now at £205, as just last week you've have been able to get it for closer to £190. As a result, you should probably steer clear of that one for now, or wait to see if anything better comes along during Amazon Prime Day early next week.
There is, of course, every possibility that even the 250GB MX500 might get a better discount on Prime Day, although given how low it is already I'd be surprised if it dropped any further. Instead, I think it will be much more likely that we'll see larger SSDs get the big discounts over Prime Day, so you're probably better off waiting to see what kind of offers you can pick up.
That said, if you're after a big SSD like this, then you should really be considering Samsung's 870 Qvo instead of the MX500. The 870 Qvo's random read and write times are much faster than its Crucial rival, coming in at 39MB/s read and 111MB/s write, versus the MX500's 37MB/s read and 73MB/s write. It's also much cheaper, as the 2TB model can be had for £190 at the moment. It's also available in larger 4TB and 8TB sizes, but with the 4TB model starting at £390, you'll need some seriously deep pockets for it.
If you'd rather see what kind of other SSDs are going cheap at the moment, then be sure to check our regularly updated SSD deals hubs for all the latest prices.