I'm also new to cs but i've been reading old posts. If you're not bothered about HD then a DM500 (clone) about £50 is a very good choice. I'm waitng for someone here to get back to me else i'm gona order mine tomorrow.
If you dont want HD then I would say DM500 Clone (£50) OR DM600 clone (£95).
If you want HD with single tuner then I would say DM800HD clone (£200 from uk but around £145 from china, as long as you dont get hit by customs). If you are going for a DM800 HD clone then make sure you get one with sim 2.01, bootloader 76 and Tuner rev L - this will mean you can use your favourite images unpatched.
If you want a dual tuner HD box then would suggest the VU+ Duo (£380) - this is a brilliant box and at the moment i cant fault it!!!