Those cards are probably worth getting graded. The 28 Star Player Candy cards did pretty well in this recent Legendary auction:
Link
One really nice thing about SGC, at least when Brian and Michael were there, was that they often let you combine shipping even if you have cards on different tiers. For example, if you have a submission where you have a few cards at the $1000 tier and a few more at the $250 tier, you can have them all shipped back to you at the same time if you request it. You can save in shipping costs this way. The drawback is that the cards would be delivered at the slower tier timeframe, so if the $1000 tier were 3 days and the $250 tier was 15 days, all cards would be shipped to you after the 15 day mark. This would be useful if you weren't in a hurry to get back your cards, and wanted to save as much money as possible. You can do the same thing if you have oversized cards. PSA does not allow you to do this, and all submissions in separate tiers and card sizes need their own separate submission and delivery fees.