You Get what you pay for
Buying plywood means shopping by price point. Plywood is a manufactured product and as such there are some well defined steps required to make a panel. Each of those steps has a cost associated with it and there is very little new in the industry that will change the costs. No groundbreaking innovation that suddenly makes it cheaper to produce a plywood panel. So let price be your guide. If you had good luck with a $65 panel in the past then you should expect to pay at least that much to get a similar performance result.
If you dealer presents you with several different options for a similar panel with a wide range of prices, it is important to know that lower cost panels are lower cost for a reason. Some step was skipped or a corner cut in order to meet that price point. This isn't necessarily a bad thing as the step that was skipped or foreshortened may not be important for your particular plywood application.
Know what You need plywood to do
How will you use plywood in your project will dictate what plywood product you need to buy. Does it need to be flat? How flat? Will you be screwing it down to a sub structure? What does the face need to look like? Will both faces be visible? Will you be machining it and cutting joinery into the panel? All of this will tell you and your dealer what is most important and therefore guide the specifications for the right product to buy. This will also help you assemble a price point list for future buying as mentioned in my first point above.