John Lott argues that training requirements have a negative effect on public safety. He also argues that high permitting fees increases victimization cost.

John Lott, Jr. wrote:
The results also indicate that permitting fees are highly detrimental. For each $10 increase in fees, the percentage of the population with permits falls by one half of one percentage point. For the thirty-one states with right-to-carry laws, this increases victimization costs by $1.7 billion. The large effect from higher permitting fees might be due to the poorest and most vulnerable being especially discouraged from obtaining a permit.... High fees are more likely to deter individuals from carrying guns when those individuals are poor. When fees are high, there may be a smaller crime-reduction benefit from right-to-carry laws even if the same percentage of the population were to obtain permits.

John R. Lott, Jr, More Guns, Less Crime, 3/e: Understanding Crime and Gun Control Laws, The University of Chicago Press, 2010, p. 181