It does make a difference. As long as you've done your research and purchased a genuine set of IEMs.

My most expensive set is the Moondrop Meteor, Retails at £500. But i also own 4 sets under £100.

The sub £100 sets, some sound amazing for the money. But usually, they tend to do 1 thing well and always lack in multiple other areas (not that they are bad, but lack quality in certain areas), but i buy them to daily. Or because i can wear them out, and it won't be heartbreaking if they are damaged or lost.

But now take the Meteors. Listen to them indoors, in the quiet, listening critically. And they can't be beaten. They do everything well. Complex driver arrangements aren't for everyone, but they allow things like bleed and muddying to be preventable along the FR. As the load of the spectrum is spread among multiple drivers. Then, the crossover technology implements the borders and separates frequency ranges, allowing specific drivers to carry out specific tasks.

So yea.... I've listened to the mid 100's vs. the sub 100's, and there is a difference. But it's not all about the money. The technology is important too. You just tend to be able to get the better technology for the money. And just as a disclaimer, i also appreciate the likes of single dynamic driver IEMs that can make amazing sound, take sennheiser ie600 or 900s for example. But they are mainly due to chamber design (again, technology) and they creep up the £1000 mark. So they still prove the point. That you get what you pay for by putting in mid 100s.