Much depends on your boyfriends favourite style of music (I.e what he is likely to want to play). I highly recommend the Yamaha FG700MS for general stuff. I have had one for over a year with no problems (I play it every day) and Yamahas are generally very well built for the price.
Don't get one with a plywood top or back if you can avoid it. You should be able to get one with a solid wood top, back and sides for around �120 ish + VAT (online price). A solid wood top such as spruce will give a better sound and very cheap guitars not only sound bad (usually), they go out of tune very often and make learning so difficult, many are apt to give up.
So around �120 plus VAT should buy a good guitar to learn on that will last for years. You might want to go to a music shop and take specific advice and hear some various models played.