The simple answer is, it depends. There is a one time sign up fee of $25. After that there is an annual fee but it is usually offset by fundraising. The cost for the entire year is $97 (I don’t remember ever having to pay that since we did some fundraising during the year).

The second part of the cost will also depend on your pack. There is a book that you will need during the year. Our pack had them donated by a fast food chain so there was no cost to us, however, if that is not your case they can be purchased here or here (it is more expensive but you will get it fast if you have Prime).

The third part of cost is the uniform. There are some money saving options here.
1. You can find the uniform shirts at a thrift store. (That is how I found my boys cub scout shirt and boy scout shirt.)
2. There is usually a gear & uniform exchange program within the pack. As kids in the pack grow and move to a new rank they will donate parts of the uniform to the pack that can be exchanged or handed down or they may sell it at a bargain so you will not have to buy brand new items.
3. Not all Packs are the same but ours did not require a uniform for regular meetings, they did ask if you could afford a Class B shirt that it be worn at meetings and outings. A Class B shirt is just a fun scout t-shirt that the pack has created that represents the Pack.