ASOS's genuine leather women's biker is the most honest entry point — real leather rather than PU, decent hardware, a biker silhouette that works with dresses and jeans equally, and fully lined for wearability. It won't develop the patina of a quality leather but it looks the part, fits well across most builds, and costs a fraction of what a serious leather jacket demands.
AllSaints makes the best leather jacket for the money in women's fashion — the Balfern uses lamb leather that's properly soft, YKK zips, and a fit that's been refined over years of customer feedback. The hardware is solid, the lining is comfortable against thinner fabrics, and the jacket develops a genuinely personal patina over the years you own it. The jacket that people ask about.
Joseph makes the definitive luxury leather jacket for women — the Perfecto uses soft lamb nappa tanned in Italy, hardware that's cast rather than pressed, and a construction quality that makes other leather jackets feel obviously inferior. The fit is precise without being tight, the silhouette works over everything from dresses to tailored trousers, and it gets more beautiful every year you wear it.