It all depends on the specific property. Major properties can be very expensive. The NFL charges $100,000 per year in upfront fees for apparel licenses. MLB, NBA and NHL are between $25,000 - $50,000. I've never worked with character licenses, but I would imagine the big Marvel, DC and Disney characters could be close to the sports leagues. Same with video game characters. Much of it depends on what you want to create and where you intend to sell. So it's a good idea to have that info handy along with projected sales. Royalties are usually between 5% - 15%.
If you are looking to work with a smaller company, it's hard to gauge what they would charge for licensing. Your best bet is to contact them and casually ask them about licensing opportunities. If you feel like a deal can be worked out, it's a good idea to consult an attorney experienced in licensing negotiations. It might be overkill to have representation during the negotiations, but it doesn't hurt to get some advice before entering into a contractual agreement.