Buying speaker cables on-line: Is this advisable?


I am in the market to upgrade my speaker cables for my system and will definitely be interested in considering used cables because of cost savings.  I've started doing a considerable amount of research on selecting cables and it's very possible that I will buy the cables on-line.  The dilemma I have is being able to see/hear all of these different cables that I am considering before making a decision.  Are there certain questions I should be asking about performance or construction when making a decision?  I have a solid state amplifier, Ayre AX-5 twenty.  Are there certain types of cables that perform better with solid state amplifiers?  Is there a way of getting performance information from manufactures like MIT, Purist, Kimber, etc?   Is there is any situation in which one could consider purchasing cables without first hearing them in a system.  Any and all thoughts are welcome as I continue this journey.  Many thanks.
phono27
Only buy if you can return. There's a website called The Cable Company where you can do that.
https://www.thecableco.com/lending-library
The variability is too extreme to rely on opinions. 
The Cable Company has a sister sight called Usedcables.com as well. For the most part reasonably priced. TMR (The Music Room) sells regularly on Agon and has a generous return policy. Some other dealers sell demo gear, usually can be returned as well. Just have to look around. 
To another post, I have a set of Blue Jeans cables. For the $$$ not a bad cable... but they simply don’t compare to the likes of Shunyata, Analysis Plus, or Transparent. I don’t know other brands first hand, as mentioned the best thing to do is try some... they all have pluses and minuses. You just need to figure out which suits your system and your ears.
Buying used is a good way to go with cables in general if you buy right you can always resell and move on to something new with little or no loss.
All the hype and opinions about speaker wire is just that - hype and opinions! No hard engineering data to prove that cable A is somehow better than cable B. It's all "my golden ears told me it is so'. The whole wire business is a clever marketing ploy to befuddle and snare the gullible and unwary! 
Note that Blue Jeans Cable assembles several gauges of Belden and one gauge of Canare for speaker cables. They are quite different in their sonic presentation. I prefer the Canare over Belden, but am using older Alpha Core Goertz cables at this time.

Its been said too many times, and I’m not sure what it really implies, but chances are that 90% of the rock, blues or soul music you listen to was recorded in a studio using Belden, Canare or Mogami cables. " A fiddler on the roof, a most unlikely sight. It might not mean a thing, but then again it might!"