Here's how you can get some easy Grade. First, put the battle difficulty to Hard or Unknown (the latter is only available after you beat the game). Then, after beating Nebilim you should acquire an accessory called Blue Dice. Equip them on someone (coupled with the Normal Dice for even more Grade), and go to the Fallen St. Binah area. You should get around 7.4-8.4 Grade per battle.
To reclaim Tear's Pendant after you give it up, do the following. Head to Cheesedonia and go to the Medical Shop. Speak with the man there about it; he'll tell you he sold it off already. Continue with your game thereafter until Cheesedonia sinks. At this point, you'll again find the man from the Medical Shop, who will tell you that he sold it to a man named Raiz, from Grand Chokmah. He wants 100,000 Gald for it back.