I own 2 model 84 pistols and was pretty much was late to the party AFTER Beretta USA quit listing them. I bought a well used, older surplus, but serviceable Model 84 pistol off of GB for $350 about 2 years ago. I believe it was the first version of the 84 and most likely from the 70s. Its in the safe waiting to be refinished back to factory standards.
About a year ago, while making my pawn shop run, I can across a Like-New +++ Model 84F for $450 with 2 factory 13rds magazines, which I grabbed up real quick.
They are still out there, but on the "secondary" markets. Also, about 2-3 years ago, they seemed to be in greater demand and the prices reflected that, but the prices have been coming down to a more fair market prices, so you should be able to find one at a good price right now. The only down-side to the Model 84 pistols are the magazines.... Beretta factory marked magazines are $45 (+/-) a pop, but the Mec Gar made ones are hovering at $19 (+/-) per magazine. I believe that Mec Gar are the "OEM" for most of Beretta magazines, so it depends on how important markings are to you.
As for its size, yes, its a big .380, but still a nice gun and a joy to shoot. I also own both the Walther PPK/S and the Sig 232, but the Beretta is a far better shooter.
Good luck!!