设每支圆珠笔X元,则每支钢笔的价格是2X+0.8元,根据题意得X+2X+0.8=8.3, 3X=8.3-0.8, X=7.5÷3, X=2.5.2X+0.8=2×2.5+0.8=5.8.答:一支钢笔5.8元,一支圆珠笔2.5元.