Each place will be slightly different in their prices but they all have a similar pricing structure. You will have a cost per slide and then you’ll need to pay for the medium that it’s delivered on. For example, you’ll pay $0.40 per slide and then $10 to have them on one USB drive. To have 100 slides on a USB drive, you can expect to pay between $35-$40. This figure will then increase the more slides you want to convert. If you had 500 slides then you'll have to pay around $160-$180 which in some places being a little cheaper or more expensive. As you can see, they're using a professional service can be good if you only have a few slides. Past a point, it doesn't really become economical to do it. Having your own converter can cut down the costs and give you a permanent machine for future slide transfer.