I went to buy some packs in my favorite channel and there are two buttons at the bottom of the set page, what are they for, and why are the prices so different?

The button on the lower left of the set page that says “Get Lucky” is for purchasing single packs with your Quidd coins for a chance to pull an item from the current set.

The button to the right lower side is the direct purchase button or DP. It should say “Buy All”. This button will charge your account the amount that it shows on the button and then give you one pack with the entire set contained in it.

What does it charge when I choose DP?

If you have a balance in your Quidd wallet it will automatically take the funds from there. If you do not have a balance it will charge your play store account.

What does it mean if my DP button is only showing “Check Listings”?

That means the set is no longer available for DP, either because it has sold out and needs to be restocked, or it is no longer available to purchase directly.

At that point you could only purchase the items through the aftermarket.

The “Get Lucky” button is greyed out, what does that mean?

That means that the set is no longer being sold directly, the only way to collect it is in the aftermarket.