Spectra s2 & medela in style advanced

I am exclusive pumping I am using the medela in style but my milk supply got considerable low, the lactation consultant told me I need a hospital grade pump but medela symphony is extremely expensive, I just can't afford even to rent it. I was reading that spectra is a hospital grade pump and have really good reviews, but I wanted to know opinions from real people. Anyone that have tried both breast; pump medela in style and spectra s2, can you tell me if spectra can be better that medela to keep up with milk supply? I really need/want to increase my milk supply at least a little. Thank you!