If allowed, see if the slide will easily slip off the frame after the slide release has been turned. The Beretta 84, which is pretty much a twin has an alloy frame. After not a whole lot of shooting the steel slide will begin to hammer the frame around the guide rod. If bad enough, you will have difficulty sliding the slide off the frame. If it slides off easily, look at the frame in the lower front to see if it's had a pounding. I learned about this after I bought my wife an 84 and a year later I started seeing just the slides showing up at gunshows. I wondered if the Brownings might have steel frames (doubtful), but have never had the chance to look at one. If the BDA has a steel frame, just ignore this post.
Both of those guns really fit your hand well and feel good. Someone needs to design a buffer for them. Good luck.
I have a Browning BDA .380 I bought in 1989 that has been shot less than 100 rounds. The slide slips off easily from the frame and feels like steel, not an alloy. I like it. I believe mine was made in Italy by Beretta.
I've seen that BDA for alot more than $300.00 I sold mine (not blue 95%+) for $450.00 (2mags and box) a year ago to a vendor at a gun show. When I was at a show last weekend they were well over $500.00. Guess it depends on the area your in.
I purchased one in an on-line auction from a very reputable family....build date is 1981, un-fired in the box w/papers (blued) for $575.00 As PhillyD said, kind of depends on where you are located and the condition of the pistol. I should add that this price does not include the auction premium, shipping to FFL etc.....