I know very little about antiques in general but I do know a little bit about Swedish antiques. I was surrounded by them growing up and I have had my own antique import business. Now I am just an avid collector (hoping for a good lottery win so I can go to my secrets spots in Sweden and buy more!)
My personal design style is to mix very old with very new. I love real contrasts. I can’t think of any other antique style that mixes so well with a contemporary style as the old Swedish – particularly the “simple gray period” 1750 – 1850. Furniture was painted gray before and long after the internationally recognized “Swedish Gustavian” period (1771-1792).
When people ask me what Swedish antique to invest in, I always say start with something simple. I would suggest a good quality sideboard/buffet, a quality bench with upholstery or a quality 3 drawer chest (each preferably with its original paint although they are rare since most of these pieces have been repainted (often many times over) in the 19th century and early 20th centuries). These items are attractive & functional. They are easy to place, easy to sell and will only go up in value (even if the price tag most often is steep from the beginning).
If you don’t buy them directly from Sweden then there are several professional and really great stores in the US focusing on Swedish antiques. You will want to work with people who live and breathe Swedish antiques and who travel to Sweden to hand pick their pieces (and are, if needed, willing to learn from Swedish experts). Do your research well and you may end up with a really lovely Swedish companion that will be treasured for generations.