There's an old saying. "You get what you pay for!"
It rings true in many aspects of life in general, more so than not, but it's a matter of balancing out what you spend to what your usage return will be.
Let's take a knife for example, if you are using it at least once a day I say go ahead and spend what you can afford to but always spend a little bit of time researching the item you are looking at.
If you a hairdresser who is careful with their scissors and clippers then spend away as you will reap the rewards sooner than later.
Groomers are spending a lot of time wrestling with unruly clients so they have a higher chance of damaging their clippers and scissors so maybe a bit of consideration to this should be taken into account, but never the less they are cutting and trimming all day long so its worth investing a bit.
Dressmaking is usually a good place to spend up on shears etc if its an all day affair.
Butchers and Abattoir workers should look at a good balance as their knives and steels should have a little flexibility to wear.
This also goes to anyone that are hobbyists with a passion or anyone who generally just likes to spend a bit now to save in the future.
A common issue I see is large companies selling things to do a job they are not designed for.
Take a lot of 5 in 1 "Pet clippers."
There's a lot out there being marketed as a pet clipper but really only useful on light coats around clean un-matted areas.
There's a reason why you see groomers using A5 blades, it's because they are designed to do the job and take a lot of re-sharpenings vs buying entire new blades.
So always try and find as many independent reviews as possible to make an informed decision, but you need to take in a decent amount to average out what seems to be the truth vs misinformation.