Is it much of a problem to bleed a brake system?

yesterday my brakes failed i had to push the pedal hard to get any response i took my front wheels off this morning and the pads look fine i also checked for any leakage then i checked my fluid reservoir it was below the dangerous mark ive topped it up again but my brakes are only marginally better, im not a mechanic, so im not sure, and im on a budget so i cant afford to take it to a garage, and if i did how much would it cost?