Ultimately, you do get what you pay for. However, when it comes to high-end furniture it is important to consider more than just the longevity of the piece. There is also the practicality of the situation to take into account.
Few people still live in homes passed down to them by their ancestors. Lives are transient and where people used to value having antiques in their homes, these days tastes and styles change rapidly. People buy more than one home in a lifetime, and purchase new furniture for each new home. While having solidly built, quality pieces is good practice, is there really a point to breaking the bank in order to accomplish it?
There are some things that it is unwise to skimp on. A cheaply constructed bed will not lead to restful sleep. You may have saved a bundle but, you'll be too cranky to notice. Likewise, an eye sore of a couch will impact your ability to enjoy your relaxation areas. If it looks cheap, you'll feel cheap. On the other hand, some of the most comfortable sofas are from bargain retailers while some of the least comfortable are from stylish, high-end stores. The misconception is that if you spend a lot of money, you can expect a certain level of quality. This is a falacy.
Further still, many people buy furniture because they have or are about to get married and move into a new home together. This is often followed by having children. Children take a while to get used to the idea that furniture must be treated with respect or it will look terrible.
One common mistake made by young couples is to purchase expensive pieces before their kids are old enough to understand the do's and dont's. Then, instead of letting kids be kids, things become really stressful. On the other hand, people who bought something inexpensive are more likely to better enjoy their children and have a better quality of life. It's really quite simple, when you spend a lot of money on something, you are more likely to be obsessed with keeping its value in tact.
Buying anything that will be an important part of your life should depend on two things, and neither one of them are cost or quality. The first is how well the piece will work with your lifestyle. The second, and most important, is if you love it. At the end of the day, it is your home and you have to love being there.