Generally if you can find it cheaper, then GG will price match. Just ask on the phone or alternatively come in store. As for discounts otherwise, you'll usually find the guys can do you a deal if you buy a couple of things, for example a head and cab together.
If it's the Newcastle store that's nearest to you, then ask to speak to a manager there once you know what it is you're after. Myself and normal staff aren't able to do discounts you see so all we'd be doing would be asking a manager ourselves!
Any further questions then PM me Probably best rather than pulling this thread off track which I could see us doing!