I *used* to just accept that they were the cheapest around for everything - but its still worth shopping around as a few things on their site seem to be priced a bit over the odds - eg £538 for a CIJ fender mustang bass, where everyone else can do one for £400.
The UK prices on their site aren't always accurate, so don't forget to work out the Uk price and factor in any currency conversion commission fee your credit card company will add on.
They don't like delivering to non-cardholder address even if you have placed a few previous orders, so everything has to be delivered to home rather than work, which can be a pain arranging for someone to be in.