The G7700 is an excellent receiver and sounds great, but it does have some Achilles Heels....I have owned two of these, I sold one (a later model) and I still have the other one (earlier model).
The one I own is modified quite a lot, has the best of the best of everything I swapped out....It makes 190watts per channel and rated THD, Nothing wrong with a standard transformer, I wouldn't worry about not having a toroidal transformer.
If the mains fuse is blown, it has likely had a catastrophic failure in the power amp. You need a very very good tech to save this beast, they are difficult and frustrating to work on.
The tuner is difficult to align as the instructions are hopeless in the manual so you need a tuner guru who can decipher the stupid instructions in the manual.
The Fluroscan display is driven by a chip which is next to impossible to get, you need to find a donor unit with one which is working and do a transplant.
There are two different evolutions of the G7700, one has TO-3P output transistors, the other has the more robust MT200 Output transistors, along with that the driver board is upgraded/changed and there is no service bulletin for this.
Also the digital display board is different in the later ones too.
We are not allowed to discuss pricing in this forum, you have to post in the Dollars and Sense forum.
However, I wouldn't want to pay that much for a non working unit, as its a huge investment in time, stress, parts etc etc.....People need to realise, non working units are not worth anything as they don't go!!