Gas hobs vary widely in specification and it's important to know exactly what type of hob is right for your living arrangement.
Firstly and most importantly if you live in shared accomodation or flats, flame failure safety devices are required by law. This safety feature ensures that the gas cannot be left on if the burner fails to ignite. This is a highly efficient safety feature and is recommended for any living arrangement.
Other features of gas hobs such as cast iron pan supports, residual heat indicators, wok burners and the overall width and design of the product will fluctuate the overall price.
There are further safety regulations when considering the width of the hob you are interested in. In order to have a wide gas hob there must be a clearance of 75cm between the top of the hob to your cooker hood directly up from either side of your hob.