Is colour printing a business essential or an unnecessary luxury? The answer largely depends on the nature of your business.
The bulk of the printing at a cafe or restaurant might be menu inserts, for example, so black and white will do the job. But an estate agent would almost certainly want colour output for window displays and for flyers to be handed to potential buyers.
If you do need colour, the choice between laser and inkjet technology is largely about the 'look' you prefer. Laser toner has that familiar slightly shiny finish, while ink looks matt when used with plain paper. There can also be a slight fuzziness around the edges, especially if you don't use paper designed for inkjet use.
The idea that lasers are cheaper to run has largely been put to bed in the business market, with some of the well-known vendors offering inkjets that have a lower cost per page than an equivalent colour laser - sometimes as much as half.
That said, a colour inkjet does waste some colour ink keeping the ink path clear when it is used predominantly to print black and white pages - whereas there's minimal wastage of colour toner in these circumstances. In any case, not all the ink or toner used by a printer actually gets onto the finished page.
Regardless of the print technology, black and white pages tend to have significantly lower coverage than colour pages. Think about it: a page of text and line drawings is predominantly white. But when you know the page is going to be printed in colour, there's a tendency to include photos, patterns and other complex images, resulting in much more of the page being covered with ink or toner.
In general, inkjets can be used with a wider range of media, including photo paper, transfer paper (for t-shirts, etc), extra-long 'banner' sheets, and printable discs (admittedly something that's needed less frequently these days). Again, that's going to be more or less relevant depending on the business's requirements.
One thing about colour printers is that people are more likely to use them for private jobs such as their kids' school projects or 'lost dog' flyers. Some employers consider that to be part of the give-and-take of workplace flexibility, while others aren't so accommodating. Certain colour printers - usually higher-end models - make provision for restricting particular users to monochrome output, as well as making double-sided print the default to help keep costs down.
So think about what you actually need to print.
If almost of it is black and white (eg invoices), you'll probably save money by buying a monochrome printer. Those occasional colour jobs can be affordably taken to your local print shop (see Why you still need a print shop) or - especially for larger volumes - sent to one of the printing companies that let you upload the document and then ship the finished result back to you.
But as the proportion of colour printing increases - especially for one-off jobs - an in-house colour printer makes increasing sense.
And as your total print volume increases, one of each could save you money if the lower cost per page of mono printers offsets the purchase price, especially if you're wedded to the 'laser look'.