A few weeks ago, I wrote about my success at obtaining a PDF copy of NESAT XII, Aspects of the Design, Production and Use of Textiles and Clothing from the Bronze Age to the Early Modern Era (Karina Grömer and Frances Pritchard, eds.) from the publisher, Archaeolingua.
Today, I thought it might be worthwhile to make an effort to find NESAT XIII, Links Between Past and Present (Milena Bravermanová, Helena Březinová, and Jane Malcolm-Davies, eds.), which was published by Verlag Beier & Beran Archäologische Fachliteratur.
Abebooks appears to still have the book in soft cover for $70.25 USD plus $18.48 USD shipping. I wasn't able to navigate the publisher site, which is written mostly in German. Perhaps the PDF option will be adopted after they run out of soft cover copies of the book.
As for NESAT XIV, the conference was only recently held (online) this summer; the volume has not been published yet. But abstracts for the presentations may be found here.
EDIT: (10/11/2021) As the commenter noted, there are a few publicly available videos of NESAT XIV talks. You can find them here.