I've repeatedly bought from megatoners and referred others. The worst batch had three DOD carts in it. The prices are so low you don't worry much about it. Seriously. $2.50 per cart is not uncommon. The batch with three bad ones was unusual. I've had batches with 0 duds. They switch providers constantly so it's a bit potluck, but the money I've saved could buy a dozen printers and these carts have yet to kill one. (unless you think ink can burn out the motherboard. I do not.)
https://www.youtube.com/watch?v=xXhVP0Un... This video helped a little. It is very hard to pry the left or right side away as the manual says. The video shows lifting from the center of the back. This bows the lid and consequently pulls the left and right sides inward slightly. I enhanced this movement by pushing inward from the right and left sides with my thumb while pulling up from the center of the back panel. This popped open the clasps on the right. Lifting the right back corner and pulling to the right, I got the clasps on the left to disengage. Once the clasps on the left and right towards the back came loose, the rest was far less stubborn.