I think that you're right about that. Lang always put a few such items into the show; they were always for sale in the shops but never really were intended to be "hot items." Rather, they were just experiments, ideas that Helmut had. Like s/s 2004's tank-tops and tees with the "peekaboo" holes cut all over (on the sides, on the nipples, etc.). Certainly, these weren't items that were meant to fly off the shelves, but were just interesting art-like ideas.
This is part of the reason why he had such a bad relationship with Prada and why his brand under Prada was never financially solvent; because he didn't have a GUARANTEED hot seller (like an "it" bag or pair of shoes) for each season, these "art" elements of his collection lowered sales. Prada tried to compensate for this by over-producing his jeans and tee-shirts, but this backfired on them because there were always tons left over that could be obtained for $50 or less by customers on markdown. So, who would pay $275 for them?
Also, another way designers make enough money to compensate their artistic whimsies is with cologne... but Lang's cologne was also a relative failure (it had a REALLY odd scent that turned many people off, sort of buttery and just plain odd). He also had a scent that had no scent (limited production of course) and Cuiron, which was a little more popular but still never really went anywhere.
When Lang owned his own label, he made most of his money from the Helmut Lang Jeans diffusion label, which still had great quality and the prices were good. Prada, in their "infinite" wisdom, dissolved the Jeans line and kept only the Helmut Lang mainline (it brought the actual jeans and tees into the mainline, lowered the quality, and raised the price), which effectively killed the profits because his mainline collections CERTAINLY weren't diplomatic in their fit or styling.