The thing is, if it makes you play better, whether its a placebo or not it is worth it. It's a bit like kids dressing up as their favourite super hero, it makes their play more enjoyable.
There's been a lot of good points here and I'd like to share some thoughts from my experience. I've been playing on and off for over a decade now both at university level and recreationally after I graduated. Because of my job I was able to travel to China and HK and play there in a few clubs there. I've noticed a few things 1. A good player can play well with anything. I've encountered some provincial level players in China and he can beat me using an antique wooden racket just as well as using a top-of-the-line Yonex racket. It's been long established that the skill is in the person and not acquired through some tool. This isn't a video game, you don't do more damage just because you got a bigger gun. I've seen high level players in Asia using off-brand, clones or no-name brands and performing very well. In fact, in Asia there are more users of "non-professional" rackets than professional rackets. This is probably due to a combination of availability, price, average earning and other factors. For some regions like North America it's difficult to even find decent clones for a cheap price. The selection is so limited you might as well shell out for the top stuff. 2. With that being said I also believe that for every player the "feel" of the racket is most important. You can be at any level, but if you can genuinely tell the difference between 2 rackets and prefers one over another then that's the one you should take regardless of price. I play in Canada mostly and with my co-workers, who are mostly beginners. I know for a fact they can't tell the difference between a Z-Force 1 and a Bravesword 12. These guys sometimes ask me what racket I use and if they should get it. My advice to these guys are "Save your money. Get your footwork down. Get your swing in form. Study a lot of tape (of yourself and pros) and work on your technique. Lastly, get a racket that's comfortable to you." I know they are going to change rackets as their skill level increases and their preference changes. There's no reason for them to buy a K9000, then swap it for a Nanoray 900, then go for a JS12 just because it's the professional's choice. But if it really feels good then go for it. 3. I also understand the attraction of a "professional" racket. I myself have purchased multiple rackets because of the people who use them (AT900T-Cai Yun, Arc8DX-KooKK, BS12KRP-LYD etc.). I know full well the desire to associate with my idols by holding the same weapon as them. But I've realised (through maturity and trial) that they are professionals who are paid to use these rackets. Unlike them, I pay to use the rackets and they may not be the most suitable for me. I will never be able to do what professionals do with these rackets. I need to find what suits my style of play and regardless of it's popularity and that's the one for me (as discussed in 2.). However, if you want a racket so that you can be closer to your idol and know that it's more for show than for practicality then buy as your heart beckons. After all, for most of us badminton is a passion and it should bring us joy first and foremost. 4. Lastly, I think for many people the most important factor in buying a racket is the price. For many husbands/boyfriends/couples the toy we get is whatever our significant other approves. My wife has bought me rackets in the past as surprises and she'll get me the most expensive one in the shop. And when I buy rackets nowadays I've got to get budgetary approval. Regardless of who or what dictates your financial situation there's a limit to what you can spend. If your budget is capped at $50 then you can't get one of the "professional" rackets (at least not in Canada, China or HK). One has to be objective when buying. Do you spend the $100 on something that is not used by a famous professional but performs well OR get a low end racket from a signature series (ie. LD or LCW)? In the end there's no single solid good reason to buy a professional racket or to avoid it. It's a personal choice much like a cell phone, car, pair of shoes or any functional good. The reality is that most of us won't be able to fully utilise all of the designed features, materials or advertised improvements. If it feels good in your hand, good on your wallet and brings a big smile on your face then it's all the reason you need to buy it.
Went into my local courts/store last month in search of a new racket. My first in 7 years with a lowish end Carlton. Picked out 5 rackets I were slightly familiar with in name but never tried Voltric 7 Duora 10 Duora 77 Bravesword 12 Voltric 5 tested them out on the court for 1 minute each (didn't have much time due to courts being booked by others). I did not check the prices beforehand but knew the Duora's were the most expensives, Voltrics were the cheaper variants and had no idea about the price of BS12. Ended up with that BS12 because it FELT the best in my hand and I liked it's speed. Of course I knew it's stats roughly and liked an idea of all round racket but really it was the feel that sold me. Turns out I got it for a good price at €110 and I'm happy with my choice! Not saying it's cheap but it's a good price to pay for an excellent racket IMO. That's what's important and only a badminton player knows this, not others judging your expenditure
Arcsaber 11 cost only $130 now at sunrise click, its an all rounded racket. For all types of player. If budget is not an issue i suggest you go for Duora 10, also not bad.
There is a certain point to this question as I have seen this come up before. If the status or financial situation of person is factored in and depending on what it is, the above does apply for sure.