The attraction of the Makita one is that it clamps the log at one end then suspends it over the 'foot' which stops the whole thing toppling over. You then make multiple cuts along the log (just as if it was still attached to the tree) and the log falls away from the saw instead of potentially pinching it. It looks as though it may handle odd shapes well, also. Best price so far including delivery is £66.99 which may be justified for something which folds away neatly and will last for many years.
Noted from many responses that making up a '3 X' trestle from wood is probably better than buying one.
Cheers
Dave R