www.ShotGunNews.com has an FFL finder.
20-25 seems to be the average.
40-50$ does seems high, but people are charging it.
Also ask if they charge tax. Some places charge you sale tax on the original cost of the item. I would love to see their tax records to determine if any of that money goes to the State. I asked specifically and don't need to charge sales tax since I am not making a sale.
Also some places charge the transfer fee based upon the retail value of the weapon, 10% is common.
Last thing to look at is, do they charge per multiple weapons or is it a flat fee.
Pete