Well, £30 isn't a terribly large amount of money... you can't get a really good, quality laser with £30, but there are many suitable cheap ones. It's your choice to either save up and get a really nice one, or spend it now on something that may break. If you can wait, I would recommend one of these for a very nice laser:
HL 405,445,450nm
Save up for the 500mW 445nm (blue) or 500mW 405nm (purple) and you will have yourself a verry nice, very powerfull laser.
First of all, safety: get safety goggles. I can recommend the dark green or red coloured HDE laser safety goggles from Amazon.com, the green ones block 405nm extremely well, and also block 445 very well, and I have heard that the red ones work well for 445nm. If you ever get more powerfull lasers, be sure to upgrade from these.
Also, if you plan on being an active member here, please add your general location (state/province and country, even city if you'd like) to your prfile, and make a thread in the welcome section as an introduction for yourself. Be sure to read the safety stickies, and If you're ever confused about something or need info, use the search at the bottom, read a sticky or two or send me a PM and I'll probably be able to help.