Linotype.com is a large online font retailer, offering a collection 10,000+ fonts for sale. The company itself is part of Linotype GmbH, which is actually the current form of the original Mergenthaler Linotype Company. They have partners in over 20 countries around the world, and hold 30+ awards from 1998-2010 for their various individual fonts and font collections.
Their top 5 sellers are Neue Helvetica, Helvetica, Avenir, Optima, and Rotis Sans Serif. Pricing for single font weights starts at $26. This is fairly affordable for someone needing only one or two types for a given font face. A competitor of Linotype.com is FontShop. Both companies offer reasonable pricing for font collections (FS does have some pricier offerings with their top sellers), although FontShop seems to offer a larger amount of fonts overall.
I would say that Linotype.com is a competitive retailer. They have a nice collection of font families on their website, and very reasonable prices as well. Their offerings seem to suit a wide variety of customers in a number of fields.