One of the great benefits of gold is the concentrated value. One kilogram of gold has dimensions similar to a packet of twenty cigarettes. The problem with ingots this size is selling them. Few people will take the risk of paying out thirty thousand pounds for something that maybe gold plated tungsten. For this reason, each and every time you buy or sell and ingot of this size the likelihood is that it would need to be re-assayed to confirm purity. Ingots of a fraction of an once, should also be ruled out due to premiums paid, as explained in fractional coins.
As a rule of thumb, own only as much gold as you can carry, I would suggest no more than a few kilos is convenient.
