Umb3r

Can anyone advise on EULAs on full perm items? Increasingly I am seeing creators demanding price fixing on anything created using there products. These are sometimes quite complex, stating individual prices for using one texture, one item, or if the item resembles the original product. Its putting me off purchasing but now I have read that these hold no weight and are not legally binding, in fact they are illegal? I was referred to this article https://en.wikipedia.org/wiki/Resale_price_maintenance I'm confused, these items are listed full permissions but it seems they have rather limited permissions. Any advice would be appreciated.