I don't consider Jamis steel bikes to be high end although I admit to not keeping up on their bikes. Are they making "high end" bikes now? To me, high end is either custom, something like a Colnago Master, I consider my Riv Roadeo at the higher end of the scale, along with some other companies, ect.

So, the most important question is what are you looking for out of a bike? Are you looking for a pure race machine or something more endurance oriented? You can buy a high end bike online provided you know what you want and have an idea of your size. Are you planning on buying complete or just buying a frameset and then building the bike out of components you get separately? If you go this route you can pretty much make an appropriately sized frameset ride closely like you want it to.

I rely on other people's opinions to a degree, but I also look at online reviews, geometry charts, whatever the designer says about the reason behind making the bike the way it is, to get an idea about if it is the right bike for me. A competent designer/manufacturer should be able to adequately describe ride characteristics of a certain bike; that would be a good source of information to go with.