Then I Need to re-educate Tourist coming over to Bali.
Some stuff made seldom after cheap cost price, and sometimes producers will use some materials that is not proper. Seldom people who wear them can itch, sweaty, smelly, and not to mention skin cancer. But not all cheap stuff could cause this.

If you try to buy any cheap shirt, make sure it doesn't smell like Vinegar. Cause the bad chemicals use might smells like vinegar.
My family has been in the business of Clothing (JOGER) in the last 30 years, and we have been avoiding this materials.

In bali its not necessary what u pay what u got. Some people could do beyond our imagination to survive life. Well thats the tips I could give u all. Regarding size changes, that i don't know. My advice is to check the size before purchase.