More expensive dies do not always equate to higher quality ammo.
Absolutely!
Dies themselves are only one part of the many, many factors involved. Quality components, quality preparation, quality assembly AND quality tools are all factors. My experience is, that until you reach the level of benchrest or long range competition, all the major die makers products are good enough to produce good quality, accurate ammunition, IF you do the rest right.
There is, to me, an advantage to basically sticking to one or two die makers, which it some commonality of parts, and method of adjustments.
However, there's no need to replace something that works, just for brand uniformity, unless that's your thing.
Most of dies are either Lyman or RCBS, a couple of LEE, and an old Herter's set that probably meets the age requirement to draw full social security, but still works just fine.
For handguns, (revolvers, semi autos and single shots) I reload for .22 Hornet, .221 Fireball, .222 Remington, .30-30, .32 ACP, 9mm Luger, .38 Special, .357 Mag, .357 AMP, .44 Spl, .44 Mag, .44 AMP, .45ACP, .45 Colt, .45WinMag, & .45-70.
For roll crimp straight wall cases, I use only a three die set, usually seating and crimping in one step. The key to ease of doing this is proper brass prep, having all cases (in the batch) of a uniform length.