Your are only 17. Save up your money. If you must, and you don't already have a good rig, save up for a new gaming rig. $800-$2000 (USD), will bank you good parts to last years.
But if you are determined, the headset for it's general use. Unless you REALLY want to do better at Osu!. Buying a peripheral for one use/game is something I can't advise. The headset. I have a G35. It's awesome. 7.1. And it makes 2 channel sound like surround.
But saving up for a new rig/ saving up period. A new rig is a good longterm investment.
But if you are determined, the headset for it's general use. Unless you REALLY want to do better at Osu!. Buying a peripheral for one use/game is something I can't advise. The headset. I have a G35. It's awesome. 7.1. And it makes 2 channel sound like surround.
But saving up for a new rig/ saving up period. A new rig is a good longterm investment.