I bought this phone yesterday, and in my opinion this is a great deal. You get 30 days of Unlimited Texts and 6 Months of Unlimited Data. With the £20 top up the phone costs just shy of £100 and if you buy something else thats cheap you can get £10 off for spending £100.
We got this and an iron as we needed a new one, total cost £119.98 and got a £10 off voucher which we spent on a Wii Game(Just Dance) immediately.
Also the phone is great so if you need a new one get this, then buy a SIM only deal and you get a great deal.