[JT118]

If I can add my thoughts if you are new to this.

If I were starting from scratch and with the benefit of hindsight:

I would get an RX 5.0 or 6.0, 2 of TX boards, and one soil sensor interface and one solar/UV interface. This will give you the same capability as the most expensive Davis station see link below.

Then, if I wished to keep cost low, from Maplins buy an anemometer £2.50,  a wind vane £9.99 and a rain gauge £4.99 using FO stuff, this is just to get you started, but beware the maplin stuff is cheap, and at best you will read a representation of the weather with little accuracy and less precision particularly the rain gauge.

With luck and perseverance ebay will yield something like this:

http://www.ebay.co.uk/itm/Weather-Statio...true&rt=nc

but you may have to wait ages to get this kind on thing:

If you want to spend more (and get far better readings) try the Davis stuff, I have a thread on the forum where I post ebay sales that might be useful, someone bought the Davis wind vane and anemometer I posted about recently for £70.00 (perhaps from this forum). Using ebay you should be able to get Davis Wind Vane/anemometer for about £70.00 or less if you are lucky and a Davis rain gauge for £50.00 or less. Don't forget radiation shields for the T/H sensors, often difficult to find unless you spend £77.00 on a new Davis one. You can make your own.

New prices for these as below but careful searching on ebay you will get for about the prices above (type "Davis Weather" into ebay search.)
http://www.skyview.co.uk/acatalog/DAV_6410.html
http://www.skyview.co.uk/acatalog/DAV_7852.html
http://www.skyview.co.uk/acatalog/DAV_7714.html

Then a couple of SHT11 and or SHT21 T/H sensors, 4 or 5 DS18B20 temp sensors (soil):

http://www.ebay.co.uk/itm/Digital-SHT21-...SwopRYkmil
http://www.ebay.co.uk/itm/New-SHT11-Humi...SwopRYfzfn
http://www.ebay.co.uk/itm/Temperature-Hu...5zqwH8aPpA
http://www.ebay.co.uk/itm/1-2-5-10-DS18B...1T2fjKXJNg

For less than £100.0 with Maplin instruments, or less than £200 with Davis, you get the equivalent of this:

http://www.skyview.co.uk/acatalog/DAV_6162UK.html

and this:

http://www.skyview.co.uk/acatalog/DAV_6345CSOV.html

Don't know if this is of interest but might be useful when starting out.