Carol,
I find stuff in every search I do. I'm not here to push my sites but it helps roll searchers to learn about the different types of things to look for if they look at the stuff that I have there.
There's more to it than looking for old coins and silver:-)
For example, I recently found a scarce coin that is what we call a die variety. Dies are sometimes improperly prepared resulting in doubling of images. When it is something called a doubled die, it is worth bucks. The one I found is a $65.00 coin and that's not bad for a cent:-) It takes some learning about what to look for as there are worthless forms of doubling too.
Most people would overlook those but I thrive on them:-)
As far as silver, that's a hit or miss proposition with the best chances of finding some being in rolls of half dollars. Most people still roll up ALL Kennedy Halves when they cash them in. They don't pay any attention to the dates.
1964 dated Kennedys (Philadelphia or Denver Mint) are made of the same quality silver as the older halves. Kennedys dated 1965 - 1970 are 40% silver and are still worth a premium. 1970 dated pieces are especially nice to find as they were only made for uncirculated sets but they occasionally end up in a roll.
There are some other collector pieces after 1970 that are made in silver also.
Just this past Friday I added a 1964 D and two 1966 Kennedys to the pile. That's roughly $10.00 worth of silver for $1.50.
I don't do dimes or quarters much for the silver but for other things.
There is a lot to look for besides the wheaties:-)
Most banks have a policy that they don't let the tellers dig through the rolls for good stuff. They treat the money as a product and they don't want to tempt employees by letting them "play" with the money.
Also, It doesn't matter what bank you get coins from. I find just as much stuff at banks in old towns as I do in city banks. I also find good stuff at bank branches in supermarkets.
It's a game of numbers. The more you look through and the more you know what to look for, the more you find.
As to how many rolls you have to buy to find silver. The coins I mentioned in this post came out of two rolls that a bank had.
Sometimes you find nothing and sometimes, you find a few coins. Sometimes you get really lucky and hit a ton!
Have Fun,
Bill