I bought my first SSD when prices got reasonably low. My intention was to run OS and apps on the SSD and keep data on a spinner, so I bought an Intel 320 80 Gb SSD, in fact two of them to run in RAID, for £270. In two months, they will be five years old and the warranty will expire. Although they still contain my SL system, they have been pretty much retired since I started running Yosemite on a daily basis. The drive still mounts daily, even if it's not accessed.
I used to run TechTool Pro on the Intels to optimize the drives once a month, until common wisdom said it was a bad idea. They've never given any indication of any sort of failure.
I've had a Samsung 840 Pro 256 Gb drive in my MacBook for two months shy of three years. I think this drive came with a five-year warranty. It cost £175. An extra 100 Gb for £100 less two years after my first SSD. Never a moments worry.
My workhorse now is a Samsung 840 EVO 120 Gb that's a month shy of two years old. It's mounted on a PCIe card and is so fast! £65! Still a year to go on its three-year warranty.
I don't worry about them other than to run monthly maintenance. Disk Warrior, Disk Utility. Still, I back them up weekly to an external HHD and an internal HHD.
My data HHDs get a daily backup. All drives will fail at some point, I just seem to retire mine before it happens.
Or, to paraphrase Bobby McFerrin and Meher Baba: Don't worry, be happy and backup.