How do you define "decently priced"?
If you start with a good quality linen, usually made in Italy, Belgium, or Ireland, the initial cost per yard is not cheap.
In the USA, good quality western european linen is priced from $25 to more than $100 a yard, especially in small (under 20 or 30 yard) quantities.
Of course, if you go down to eastern european linen, or even chinese stuff, the prices fall. But it still costs around $12 to $15 a yard in most fabric stores.
In the USA, you have a textile tarif maximum of about 11%, and there are exceptions that can make it even less.
In Argentina, the textile tariff is around 26%- but that doesnt include customs brokerage fees, misc government fees, storage costs while processing, and, of course bribes.
So, at the very least, the landed cost of linen, even cheap chinese stuff, is going to be 15% more than in the USA. Probably more like 25%. Thats without any additional markup.
Thus, an Argentine retailer MUST sell you the fabric for at least a quarter more, before even considering the fact that the Argentine business taxes can approach 50%, that they must pay their employees for 13 months a year, and on and on.
My guess is that if you take the US price, and double it, that would be an equivalent cost and profit margin for an Argentine retailer.
All that said, there are several stores in Once that have unbelievably beautiful fabrics from all over the world, including good italian and belgian linen. But you have to pay to play.