Tony is right, the Garrard and SME 3012 are appreciating assets, The Linn is going nowhere value wise. However, when you see the prices paid on Ebay for old Linn Basic tonearms I wonder, will the same thing will happen to the Ittoks?
As for the LP12 Lindsayt has a point, the parts could be worth more than the whole.
The SME 3012 could be worth as much as the Linn and Garrard combined, whatever you do, think very carefully about all the options you have before selling.
Errol