There are "qualifiers" that can decrease the grade and value of your card. All prices on this site are based off an "EX+" scale, so with any of these factors, the price will more than likely lower to an extent. Below are four titles with basic grades. I am definitely not an expert, but these are simple examples to show how prices can be determined on Wacky Packs.
Disclaimer: These four grades are not the only ones to exist, but they are basic examples within several others that likely don't need mentioned.
MINT
EX+
VG
POOR
MINT: This card will have perfect corners, proper centering, no toning, and a clear image. Also, it should have a clean back. There are also some more subjective bits, such as roller marks not being present, but whether or not that constitutes it being mint or not is debatable.
EX+: This card will visually still look clean. It will have good corners, maybe not perfect. It should be mostly centered if not perfect, a clear image, and a mostly clean back. This is a card that is more forgiving than the MINT grade. These are also likely allowed to be slightly toned as some collectors don't mind it as much as others. The cards on this site are priced by this grade.
VG: This card will have less appealing features such as slightly damaged corners, possible centering issues, toning, and a less clear image. Also, the front and back may not be perfectly clean - whether a factory imperfection or not. At or past this point, cards may be considered "filler" because they are not too visually appealing but should still count as a part of your collection.
POOR: This card has one or more cosmetic issues that physically ruins the card. Whether it having paper loss, a lack of a border, creases, tears, marks on the card, or all of the above, it should still be counted as poor. And, your collection is likely not considered complete with cards like this within it.