Weighing a carpet to determine wool quality is very unorthodox. However, as I'm sure you can imagine online we are at somewhat of a disadvantage in terms of having the ability to inspect your rug. I can tell you for a fact that lower quality wool which is coarse and dry will have a lighter weight than that of a nicer quality wool. While I cannot say for sure, it does not seem as though this rug in question has does not have a poor quality wool, but this can't be ruled out entirely. For a rug of this size to have a 60 lb weight and 75 sq. ft. you're probably in ok territory in regards to quality. Had you said it was ~45 lbs or lower, I would be suspicious.
How much did you pay for this AMC rug and where did it come from? While I would be happy to suggest any certain stores, I think this should probably be done through a private message. let us know specifically what type of rug you are looking for in terms of design, quality and price point, and I can let you know from what I've seen. There are sellers out there I can absolutely tell you to avoid if that helps, but do know, that even some good internet sellers will have their junk or seconds goods rugs. I know Krow has had some good experience, once you have found rugs feel free to post them and I can comment on what to look for in each specific type of rug.
Call it cliche, but rugs are like wine in some ways. Just like certain wines have their good and "bad" years in different countries vineyards, etc., there are certain things to look out for regarding rugs from particular countries, designs, types of weaves etc. Each type will have typical elements to watch out for. For example, if you're interested in older sarouks, it's important for buyers to know about painting practices. In regards to Heriz rugs, it's important to understand that many sellers call a rug a Heriz, when in fact it may be a rug of coarser quality that is not actually accepted in the industry as a "Heriz" carpet, but rather a Meriban or other. Jaldar rugs, or double knotted rugs are well known for their high susceptibility to moth infestation. Tribal rugs may have issues with color run, irregular design, etc. You get the point I'm sure. I'd be more than happy to detail on specific questions you should ask any seller prior to purchasing. Just let us know.