Shapewear underwear

Hi, I was just wondering , if more expensive shapewear actually works better than cheaper stuff. I bought shapewear shorts from primark and they're very tight and they do shape to a degree I suppose, but they're not really giving my stomach the supporting really want ! so has anyone bought both and can say either yes, get a decent pair they're so much better, or no, if these aren't working nothing will.  lol thanks x