Resale potential for collectors isn't their concern and it shouldn't be. For one, the market and flippers determine those values. Two, resales don't bring them money, sales do. Resale potential is really a byproduct of several factors which would be more important to evaluate in business sense.
About open ES, that's usually on the highest priced collectibles, like LSFs. Those highest valued items will have more limited ownership regardless, because they are expensive. The average middle class collector cant reasonably spend $1000+ on a statue when bills need to still be paid, so having an open ES isn't as much of a big deal. Most of you will never own them, and at those prices most people who buy will probably not buy with the intention to flip. In reality many will express interest and want but ultimately won't buy, no matter what they say, open ES or not, most can't reasonably afford it.
This is why I feel forced to buy these hot toys dolls because they have such really good likeness (most of the time). 
