so with these cheaper ones from Ikea, could you install it into an already existing cupboard? or do you buy the whole cupboard and have to replace your cupboard with it?
they look good, looks like definitely a better option to having just a pull out cupboard with just shelves, if you can't afford the Haefele one?
It's better to go to the store and check if you fit them into your cupboard. But depending on the type of corner cupboards you have, it shouldn't be a big problem installing into your existing cupboard as long as it fits, just a bit of fiddling around. Check out these links to see which corner cupboard is similar to yours. You may need to add a post to mount the units on if your corner cupboard is the rectangular shaped one.
rectangular shape:
http://www.ikea.com/au/en/catalog/products/S29854116
L shape:
http://www.ikea.com/au/en/catalog/products/S39854309