update 月保费用改成300

mec-biz/src/main/java/com/ym/mec/biz/service/impl/StudentInstrumentServiceImpl.java

@@ -69,7 +69,7 @@ public class StudentInstrumentServiceImpl extends BaseServiceImpl<Long, StudentI
             throw new BizException("所选乐器不存在，请核查");
         }
         Integer userId = studentInstrument.getStudentId();
-        BigDecimal orderAmount = new BigDecimal(300);
+        BigDecimal orderAmount = new BigDecimal(sysConfigDao.findConfigValue("maintenance_price"));
         BigDecimal amount = maintenancePayDto.getAmount(); //扣除余额之前的金额
         if (amount.compareTo(orderAmount) != 0) {
             throw new BizException("商品价格不符");