Plantronics DSP 400 headset microphone
I've been using Plantronics for many years now. They are top-quality headset microphones that you won't be disappointed with.
If you shop around then you can buy a pair of Plantronics DSP 400 microphones for as little as £30. But realistically expect to pay around £40. However, what I want to bring to your attention is how the microphone headset connects to your computer. Some of the cheaper versions use a jack plug to connect to the audio and speaker part of your computer. They will require a soundcard in order to work properly. However, if you opt for the USB version then no soundcard is required, you simply plug them in and you are ready to go. If you do purchase a pair of Plantronics DSP 400 which only have the jack plugs then you should also get included with the package a USB adapter which enables you to plug the microphones into a USB socket. Unless you've got a good soundcard then I would always advise you to use a USB connector, or purchase the USB only version of the DSP 400 microphone headset. I found that the jack plug version don't work that well with Dragon NaturallySpeaking and I've had problems getting the microphone to dictate accurately. On the other hand, the USB version is absolutely fantastic and dictation is almost flawless when using this type of connection.
So there's nothing wrong with going for a cheaper version of the Plantronics DSP 400, just try and find out whether they come with the USB adapter before you do hand over any money.