Last time I checked, Microsoft Office was available for about $150. That's a lot of money if all you really need is a spreadsheet and a word processor – especially when there are excellent alternatives.
OpenOffice.org is a free suite of office software that offers most of the features available in MS Office. OpenOffice comes with "Writer", "Calc", "Impress", "Draw", and "Base". These programs can be compared to "Word", "Excel", "Powerpoint", "Paint", and "Access", respectively. I use OpenOffice personally, and I rarely have any problems using it to open, edit, or save Microsoft Word documents.
LibreOffice is a spin-off from OpenOffice. It also offers a suite of tools that are similar to Office. One of the major differences between OpenOffice and LibreOffice is that OpenOffice is now run by Oracle. Oracle is a large company who recently acquired Sun, and, in doing so, also acquired the open source projects that Sun has been maintaining. LibreOffice is run by The Document Foundation, a community-based foundation with no corporate origins.
Microsoft Office is a time-tested, feature-rich suite of applications that is pervasive and widely accepted. However, spending $150 for each computer in your business could very well be overkill if you're not using all of those extra features. I suggest downloading one of the free alternatives and giving it a try. It's FREE, you actually have nothing to lose this time.
No, sadly Macs aren't free. But – you could get a good laptop (check Woot.com for good deals) and then put Ubuntu on it and run OpenOffice as your Office suite. It's not as hard to deal with as it used to be, and I've found that this is usually a good solution for basic computer users.