The cheaper ones have barometric trend indication or weather forecast symbols. The trend indication is really all you need but personally i would not be happy with anything less than a pressure reading with history as well perhaps.
Do you wnat a remote temperature sensor?
Presumably though you are not looking for one with wind speed and direction and rainfall recording.
I bought a cheap radio controlled alarm clock from Maplin. It did not work and its replacement only worked for a short time so I am rather biassed against cheap electronic gadgets from Maplin. The multimeters seem OK though.
I bought a wireless Oregon five years ago with the usual anenometer, pressure, temp/dewpoint, rain vessel etc etc. At the same time a friend bought one of the Davis range. In five years he has never had a problem with any of the eqipment or sensors, I replaced all my sensors, the anenometer blew away and it finally all gave up 12 months ago when the display died.
I suppose I could have been unlucky and got the Friday afternoon jobbie but if I bought another one it would be a Davis
Is there an Aldi anywhere near you? They have one at the moment for £18. I got one for the boat a year ago and was sufficiently impressed to get one for the house as well. It does what it says on the tin and gives a digital pressure reading plus a graph of past readings so you can see the trend.
You can pay £100+, but unless you really need the (few) extra bells & whistles, I can't see the benefit.