Nice looking, well built, can make a very good cup.  But, like all home Gaggias, built in the last 25 years,  there are compromises in the materials used. 

The brewhead is BRASS and the boiler ALUMINUM.   Since I service and repair espresso machines  on a daily basis,  I see the effects of the corrosion caused where the brass and aluminum meet.  It is called electrolysis, and occurs whenever two different metals meet and contact, in the presence of water.  In this case, very HOT water.

Result?  Corrosion causing leakage at the interface of the (now corroded) boiler and brewhead. (The brewhead NEVER corrodes) Process takes as little as two to four years.

Fix?  Replace the boiler [or resurface the seal area] and boiler seal.  Cost varies, $110 to 150, plus shipping.

Depending on the housing material, rust can also form above the water reservoir, and in corners where water may become trapped.  Stainless and plastic machines, do not have this issue.

ADVICE:  ~~~~  Be certain that the boiler is completely empty and DRY if one is to store the machine in the long term, otherwise the water permits the corrosion to continue.  NEVER NEVER store or ship an espresso machine where it may be exposed to freezing weather -- unless the boiler is drained!  Otherwise SEVERE damage may result!  Always DRAIN the boiler.

Never, ever use vinegar, generic acids or other home remedies to clean / rescale the machine!  Use ONLY commercial products intended for such use and FOLLOW THE DIRECTIONS!!

And a word to the wise: for similar $$$,  one can find good machines that have ALL BRASS AND / OR stainless steel guts, that will not corrode in normal use.

BTW -- I SERVICE, but don't sell Gaggia machines, so I hope you find that my remarks are  objective.

Dave 877 286 2833