Hi Matt, welcome to the forum. Assuming your looking to buy new there are a few decent kites in the £50-100 range.
HQ Maestro 2 - around £100 and a really good allrounder that comes with a decent set of lines and very trick capable.
HQ Jive 2 - around £70 - not bad and a good set of lines but not as good as the Maestro.
Prism Hypnotist - A bit on the heavy side but well built and trick capable you can get these at the moment for £99 at Kiteworld.
Prism Quantum - A bit more basic and not so tricky but built like a tank - pulls like a train! ( wouldn't be my first choice)
Spiderkites Zodarion - decent kite and tricky - a bit different from the usual.
The £50-150 range is a bit limited in the UK, lots of cheap kites and some nice expensive ones but not much in between.
You also want to look in the sales section for some secondhand bargains!
Current Bag:- HQ Shadow, Spiderkites Zodarion, Flying Wings Soul, Old blue HQ Jive , 'PAW' modded HQ Maestro II, Delta Hawk,