It took me a while but I think the $19.99 only differs in description in the word "adjustable" which probably means you can move the bulb up and down within the enclosure to change the spot size.

I've not used these IKEA ones, but I've used similar ones to put light in some window alcoves. The little spring and hinge clips on these that hold the fixture to the ceiling look a little nicer than most (which are usually just pieces of spring metal).

Ron Natalie, that's it - thank you! The $19.99 model is adjustable I guess the bulb can be aimed/angled whereas the other version is fixed downwards. The adjustability would be useful especially in the kitchen, so we will go with those. I've seen them in person and they are of very good quality - comparable to fixtures costing 4x more that I have seen, so we are pleased to have found this option.

$19 for a fixture. Sounds like quality.

4" fixture without lamp, $20 isn't too out of line. They go for about $35 at the home centers when they include the lamp. IKEA wants another $11 for the lamp.

I have purchased and used a variety of Ikea lamps and lighting fixtures in my home over the years, and have always been surprised at the good quality for the low price. They have performed just as well as, if not better than, other more expensive fixtures I have bought elsewhere. I would not be concerned that the relatively low price of the fixtures the OP is asking about indicates a lack of quality. I once needed specialty spot lighting fixtures for artwork and bookcases and was willing to spend hundreds of dollars for what I needed. However, the most nicely designed lights I found were at Ikea for $13 apiece; they're still working fine after 10 years.