Soldering irons generally are not expensive. Antex which is a fairly reputable soldering iron brand (as far as i understand) sell them as low as 10$ on amazon
However when you get into a DC soldering irons you do start getting into complexity that isn't as cheap to do safely.
They are cheap but with the exception of a few product aren't that good of a value for money for what you get.
Their soldering stations are rather anemic and getting bits is rather hard (they also have a very limited line of bits to begin with).
Their gas powered portable soldering irons are quite good they don't overheat, have decent control and are well built but their electric ones are simply a miss these days.