JBAU, there is a quite difference in premium between Ainslie and Scottsdale bar both are primary and secondary market.
It's like comparing Royal Gala and Fuji, both are apples, but it has different price/taste/texture.
You need to figure out what is your buying strategy (ie low premium or premium brand) and what is your exit strategy (how you going to dispose your metal when the time is come).
Or is your question what to choose if they are on the same price?