Is that 70p for a set or for individual strings? For a set, that's far too cheap unless they're stolen and someone is desperate to off-load them. Steel or nylon?
If possible, I'd only buy one set to check what they are like. Then, if they were okay I'd buy another few sets. The thing is, I've been playing a long time and I know what type and gauge I like way. As a beginner you could buy lots of them and then when you develop some ability find ther are too heavy or light for you. I guess that if I was sure the strings were good (which seems impossible at that price) I'd buy maybe twenty sets.
I remember, in the seventies I think, I found some really cheap electric guitar strings on mail order. They were around £1.50 a set. I found that the plain strings were okay but there was always a problem with at least one of the wound ones. I decided they really weren't worth the trouble.
The advice to try to get some extra high E strings is good if you use steel strings but not for nylon strings (the high E is no more likely to break).
Remember you can only use the type of strings (steel or nylon) that your guitar is built for.