As everyone else has said does depend on the scent. If I had a 6 oz. Plumeria candle going then I would only say maybe a room to two rooms with of scent. If I had a scent like Lilac going then it will fill the whole floor of a house with a scent. I make mine all with paraffin too.
I also looked into glass baby bottles about a year ago and gave up. Now I have a lady that saves her glass baby food jars for me and I use those. They turn out really cute especially with the ribbon tied around the top.
I am in the process of setting my website with Prairieannie and am almost done and can't wait to see the final product. She has been so much help and I would say to give it a try. It is a lot of work and time but so worth it when you are done.
I would probably not buy these for the fact that the coffee beans are not wax. You have to think you are putting these above a candle and that makes them HOT!!! I would be afraid of them catching on fire. Maybe you can search a little more for someone that makes melts with wax coffee beans.