The best bang for the buck will be with a used gun by far. Let someone else take the hit in depreciation when buying new. Often one can find decent examples for under $1000- especially if it has fixed chokes and 26" barrels. There are two fixed choke Browning Citoris at a small gun shop nearby. The asking prices are $600 due to configuration and barrel length. The one has been carried a lot but doesn't look much fired. The other shows more range use with a decent amount of time in the field. I am tempted to pick up the one but really would like at least 28". 26" and shorter do not balance as I like which makes them a bit more demanding to shoot well. I shoot them well but averages in targets and birds trend higher for me with longer barrels.
Weatherby made by SKB, SKB, Browning, Beretta, Miroku, and then Winchester 101 are the best deals though one can sometimes find a decent Superposed or Remington 3200 in that price range. In the price range in the OP the options for used are nearly limitless and even new has a lot of opportunities. As mentioned, borrow or rent as many different guns as possible before making a decision. Prefer Browning/Miroku over most others but shoot Beretta and most others as well.
I don't worry much about gun fit other than the balance is pretty close to how I want it. Length is not a great factor if it is fairly close as short or long are both easy and fairly cheap fixes. A low comb is typically a deal breaker as raising it is harder as is a gun with too thin of a comb or stock as the comb can bite and there is no wood to remove if needed to bring the eye behind the receiver. Bending a stock is expensive, time consuming, and is not guaranteed to work. A good 98% of the time it is wasted advice to tell someone to get a gun that "feels good" to them as that fitting advice invariably means to get something similar to what they have which is unlikely to fit. Unless one has been fitted by a good stock maker and paid close attention and asked questions or has learned the hard way through many tens of thousands of shells (and typically with good advisors/instructors who have an idea on gun fit) it is pretty slim chances that they will pick out a gun that fits correctly. One can adapt to some guns better than others but adapt and fit are two different subjects.
