Many inexpensive modern scanners come with an attachment (one brand calls it a "light lid" to facilitate transparent, instead of reflective, scanning. The software they come with should have a setting to automatically deal with color correction for negatives vs. slides.
As an example, the HP entry level scanners (3970, 4070) both support slides and negatives. These are a $99 and $129 unit, respectively, with 2400dpi support. That's just enough for getting an image that can be posted for viewing online.
So if you're scanning just to post view-size images on the web, one of these should be adequate. If you are scanning to make prints or publish, then you'd want to look at the higher levels of dedicated slide/negative hardware up in the 4800+ dpi range.