mine is steel and some sort of plastic/polymer for the top, its by far the best desk ive ever owned.

I have one of their cheapest desktops with like third from the bottom tier legs and it's been going strong for about 8 years because it's in a low traffic area and only used for a laptop and a few desktop items. Is it made of cardboard and tin and good intentions? Yes. Will it crumble like a stale cookie if I ever damage it in any way whatsoever? Also yes. But so far so good, and for $40, it's already lasted like 5 years longer thsn i thought it would when i bought it.

On the other end of the spectrum, I used to have their ALEX desk and it was sturdy as hell, and my old JERKER was a fucking tank. Only reason I don't still have them is I needed to downsize.

You spend bottom dollar, you get junk. But, Ikea's "junk" will still outlast damn near anything else you can find at the same price point. Like shit, I have some of those cheapass LACK side tables I got in college that are nearly through their teens now and still hanging in there. Not everything has fared as well, and I'm much more discriminating and scrutinous in my purchases because of that, but overall I'd say I've been generally satisfied with the longevity:price ratio, and often pleasantly surprised. There are very few stores about which I would say that.