Broken plastic gadget on blind
Super gluing it back together may work, but probably won't work for long if you open/close the blinds somewhat regularly. You'll probably need to replace the part sooner rather than later.

It's possible that you may be able to purchase a replacement part, but I don't think it's likely. Unfortunately, especially for the lower priced items, I think they're designed for replacement, not repair, but you may be pleasantly surprised!

Try going to your local big-box store and head to the window treatment counter. Bring the blind with you (or at least know the brand) and see if they can order parts. If that doesn't work, try a window treatment specialty store. They may have some replacement parts in stock that would work with your blinds, even if they brand doesn't match. 

Barring that, I think you'd have to replace the whole blind unit. These seems to be more of a low-end unit, so, unless the window is huge a replacement should be reasonably priced (under $50 where I live, probably under $30 if the window isn't too big). Even huge windows (I've got a couple in my 100+-year-old house) will be under $100 to replace the whole thing, unless you go with a "fancy" version or have to custom order to fit the window size (wider or taller than they stock).

If you have to replace the whole thing and if this is a pretty common "standard" type of blind, it's possible that all you'll have to do is unclip the blind from the 2 or 3 metal or plastic mounts that hold it into the window frame and snap the new one into it. Compare the clips that come with the new one to the ones you already have up. They may be close enough for the existing clips to hold the new blind. If they look pretty close, give it a try. Don't force it too hard - you know about how much effort it took to get the old one out, that's approximately how much effort it should take to get the new one in. If you think you're exceeding the removal force to try to get it in, it's time to stop before you break something.

If you have to replace the clips, it's not difficult to unscrew the existing ones and screw in the new clips. You'd want to drill pilot holes for the mounting screws for the new clips to ensure you don't split the wood in the window trim. Note that it's possible that the existing holes may line up pretty well with the holes for the new mounting clips, even if the new clips are a different shape than the old ones, often they use slots instead of holes to allow for adjustment - use that to your advantage if you can. The hardest part is making sure that the clips line up square to the front of the window frame and are the same depth from the front of the frame (assuming the blinds mount inside the window frame). Take your time, measure and mark, then measure and double check your marks, then measure and triple check your marks. It's easier to change a pencil mark on the window frame by an eighth to a quarter inch than it is to make a new hole and eighth to a quarter inch away - you'll end up having to move the whole clip. (Not the end of the world, but you'll have more holes that you don't want to look at.)

Once you've got the pilot holes, it's simple to drive the screws and the new blinds simply snap into the clips.

The new blinds will come with exact instructions on how to install them, be sure to follow those for exact details.