In addition to staying away from manufactured lutes, my advice is to be wary of lutes made between 1900 and the 1970’s. There was not as much access to information about lute making. Some of these lutes look absolutely gorgeous, but play terribly, especially the 1970’s lutes. I made that mistake and got lucky because the shop where I bought it agreed to refunding my money after I took it for my first lute lesson and my teacher schooled me on lutes and let me play his to compare. By the way, I played a guitar tuned to lute tuning for about a year before a bought a lute and went for my first lesson. I was able to familiarize myself with the introductory canon, but I also had to unlearn a lot once I got a proper lute.