You have heard it's all about the glass. But I must say, it's has a lot to do with the monitor as well. I have an imac 27" at home that I do most of my work on for LR, PS etc .. I even develop for ZeissImages.com on that computer. For the most part I think my photography is OK, when I do my uploads from home and view the picture on my nice monitor they come to life. Even the website has life to it. Nice and vivid. However, when I view my pictures at work, my laptop, or a monitor that does not have a glossy screen, my pictures look like junk. To be honest, I would be embarrassed to take credit for some of my pictures when seen through a poor monitor. It really does make a difference.
I don't own a computer store but I must say, along with your nice camera gear, one should also invest in a nice monitor.