I can chime in that Pages is good BUT don't take Mac enthusiasts gushing that completely to heart. If you need rich Word compatibility, Pages can't handle everything. Things imported will change. Things exported to .doc will change too.
If your need is such that you need to open and close .doc files so that content isn't changed, you need Word. If you can live with things changing, Pages might fly.
Office on the Mac is still available for less than about $130. Alternatively, if you want maximum compatibility with Windows Word users, consider installing Parallels or similar and a Windows version of Office. If you work somewhere with an IT department, you might be able to buy just parallels and they can give you an installation of Windows + Office.
I personally love Pages/Numbers/Keynote and use them often. But when I need to work with Windows files and page compatibility is crucial, I fire up Parallels and do the work in Office for Windows. It's the only way to be certain to maintain full compatibility with Office for Windows files. Every other option will have some compromises.
All that said, if perfect compatibility is not essential, iWork does a great job importing & exporting .doc files (just not perfectly in all things that can be done in Word or Pages).