Some slide scanners require you to scan to your computer, one at a time. In the consumer category, these can range from under $50 to over $200, and generally, more money gets you better quality and easier workflow.
Make sure they have the technology to reduce or remove dust spots, which is very important with these old slides. Slide-scanning services can deliver very high quality scans of your slides that will look good even when printed on 8x10 paper.
If you want better quality, you can make less of a dent in your wallet if you can afford to wait. How fast can they turn the job around? Some places will take a couple weeks, others just a couple days, and that may come at a premium. Considering the cost of home alternatives-and considering how often you'll be shooting slides in the future-these prices are very reasonable. This can vary dramatically, from $50 for 400 slides, to nearly $100 for 250 slides. If you have a lot of slides, the beauty of a professional slide digitizing house is that they can process them much quicker and generally better than you will be able to on your own. Go to, and search for 'digitize slides.' There are a number business that will be happy to do the work for you.