I'd agree with this. They tend to sell on this forum for between £500-600. If it's in good nick, then it would be on the higher end. The mags are also rocking horse shit, so they're probably worth £50-£75 IMO. But I don't think @rocketdogbert's estimation of £100 is unrealistic given they are a limited commodity.
I'd take the whole kit off your hands for a slightly used Jar of peanut butter and a sealed squirty bottle of Heinz Ketchup