£5 ?! (plus postage too?)
Blimey, that's a fair good markup.
Is it the microphone or the headphone one that is giving grief?
The standard GA headphone socket is a 1/4" (or 6.3mm in metric) mono socket a suitable from Maplin is
given here. (£1.07 at time of posting). In the Greater Manchester area alone, there are shops in Stockport, Bolton, Cheetam Hill, and Oxford Road (Manchester, opposite the BBC) - so just find your nearest one. If need be, take in your headset and show them the connector. Another option would be to buy online from
Farnell. (34p at time of posting, you can get a 'pro' version for 63p too) or say, from
Cricklewood for 30p. I found a cheaper one again from '
JPR Electronics' at 17p so it's getting silly! (never dealt with them). Don't be put off by these low prices, they are making a healthy margin on these, and are most probably coming from the same factory.
As Nutloose said, any radio repair shop could do it for you but they can be a little bit scarse on the ground. Another option (if you don't get to contact me) would be to find your nearest '
Amateur Radio' club, any one of them would be more than happy to freely help you.
T.