Bedding is critical no matter how you look at it. In some receiver designs and stock designs more then others but all critical for long term consistant performance.
Stock design will determine which type of bedding is correct, skim, pillar or block bedding, As such, cost will be dependant on the type of bedding you need.
That said, if you have a factory rifle that is shooting poorly, do not expect that simply bedding the rifle will turn it into a 1/2 moa rifle. As mentioned much more to it then just the bedding but bedding is a critical aspect of a quality, stable, stress free rifle system.