Welcome to the forum, and thank you for your service.
Most of us, are looking for a knife that makes us as efficient as possible in the kitchen. Japanese knives have very hard steel, that allows their knives to be thinner, lighter, and sharper then their western counterparts. It also makes them more fragile. When a Japanese knife runs into something hard, it will chip. A western knife the edge will roll, with its softer steel.
Japanese knives have their own style of cutting, known as push cutting. Western knives are meant to be rocked.
Japanese knives require more upkeep then western knives. In general the sharpest and easiest to sharpen knives are made out of carbon steel, which are reactive. Carbon steel knives need to be wiped down on a frequent basis. There are Japanese knives made out of stainless steel. Stainless typically doesn't get as sharp as carbon.
To get the most out of a Japanese knife, a person needs to learn how to sharpen or send their knife out to a professional sharpener, such as Dave, who owns this site.
The problem with expensive knives, is that you or you wife, don't have the experience to determine your preferences on features or qualities of a knife. A $500 knife does not cut twice as well as a $250 knife. It might be might perform 10 percent better then the less expensive knife. At the higher levels, your buying from a well known maker, better fit and finish on the knifes. The $1000.00 plus level is custom knifes. There are some amazing examples from the makers in their sections, on the bottom of the forum.
If these are going to be your wives first high end knives, I'd recommend either the Miyabi line or the Kramer Zwillings, from Sur La Table. The Kramer Zwillings, are a joint project between Bob Kramer a custom knife maker and Zwillings. Kramer knives go for extraordinary prices, between $5,000 and 10,000 on E-bay.
The Kramer Zwilling goes for $300 - $350. It's made out of the same carbon steel, Mr. Kramer uses in his custom knives. It will rust if not taken care of properly. It's a knife that will fit a variety of cutting styles.
The Myabi's are modeled on Japanese knives. They are clad in Damascus, have great fit and finish, and are made out of stainless steel.
What makes them so attractive is that Sur La Table, has a great return policy. If you don't like the knife for any reason, and after any amount of time, you can return the knife.
Hope this helps,
Jay