Huh? H&M has linen suits right now for less than $100. The fit is pretty crappy, but they're pure linen. Old navy is selling linen and linen-cotton blend khakis again this year, I have a couple pairs of last years model and they're actually nice casual pants.
The fabric is not that expensive. Nice linens perhaps, but the basic grades seem to be only a bit more expensive than cotton.
Sorry, I stopped paying attention to H&M when my dad got a job.
Any suitmaker with any sort of respect for his business would not source linen from the same place as H&M even if he could. Linen is very expensive when it comes from good mills that tailors use. The cost of linen itself for a suit is way over $1k. You're not going to find that kind of linen at H&M, nor will you find H&M prices in MTM. But who knows, one of the online guys like Thick as Thieves might do it with fake made in england linen from china that pills up and falls apart.