There are two "categories" of commercial styles out there (at least according my opinion).
The first category are real "pro-styles" created by professional programmers and they cost a lot of money. You have to choose carefully what you want but after purchase you have a valuable addition to your styles library.
The second option is cheap bundles with 450.625 styles costing 19,99 USD
You can easily understand that most of the this styles bundles are pure garbage...
Of course you will find a few good styles and many styles suitable your performance needs but you have to search a lot... Scanning 450.625 styles will take you years...
Of course there is always the 3rd option to get the free styles from this site, you have to invest time to download and organize them, but after scanning you will find many good styles suitable for your performance needs. Note that almost all this "mega bundles with 654.758 styles" contain the free material for this site, they just steal the material from this site (plus sealed material from other sources...) and the "create" the "984.664 styles" mega-bundle...