Selling 1b (billion) Pet Simulator X gems for 4,375 dollars USD. Doing basic multiplication will determine it is about equivalent to 350k (thousand) robux. If you would like to check for yourself here are the numbers: 11,750,000 gems for 4,500 robux Gems: 11,750,000 * 5 * 10 * 1.75 = [1,028,125,000] Robux: 4,500 * 5 * 10 * 1.75 = [393,750]