There seems to be an ebb and flow to SSD prices. For awhile prices were dropping and you could pick up 512GB ssd drives for as low as $285, but now the prices have spiked back up to around $400 for those same drives.
Samsung’s 840 series SSDs are currently clocking in at around $334 for 500GB which is around $100 less then the competition, but there is a reason for the price difference. The 840 series uses TLC (triple level cells) as apposed to MLC (multi level cells) or SLC (single level cells) which means two things. First, it can store more data with a smaller number of chips which decrease the price per unit. Second, it has higher read, program, and erase latency which puts it’s performance somewhere between generation two and the current generation of SSDs on the market.
The second issue shows up as a problem for random reads and writes, but for big sequential reads (which is the most common in video editing) tests still look very good. Even though the Samsung 840 isn’t going to be the fastest drive on the market for your operating system, it still looks like a pretty good value for an video editing scratch disk.
If you are in the market, you might want to check it out. Not sure how long the sale will last before prices float back up.