One generator that I like is the Marconi 2019A or the HP 8467A or HP 8657B, with advantage for the 8647 because of the dial's, and they could be cheap if you wait, I don't know about performance.
My objective is one above 1.5GHz, but still looking for one at affordable price.
Buying from US will be little harder, since here we pay, Invoice + Shipping + 9€ = total value + 23% VAT
Let´s say $400 for the generator, $100 for shipping, 9€ fix amount at customs for opening the package, the you've the price, now add 23% on top of that, and it's the final price that the generator will cost you.
We don't have Tax in lab equipment, measuring, Ham radio, etc... but we do have 23% VAT.