First of all...
If you want quality product don't buy Robotech stuff.
Second,
If you buy some toy that is not mint in seal box, make sure the seller never had it in the bathroom...
Third,
The Yamato product in the VF-1 serie seem to be a sure thing, you get exactly what you pay for, you can get in ebay a 1/60 VF-1As non fast pack compatible for anywhere between 30-40 dollars, at least last time I checked. And the more detailed and complex 1/48 VFs go for a couple of hundreds(not sure of price range) but many here in the forums are very happy with them.
I only have 1/60s and I am cool with them.