I will give you some tips to make sure that you are getting what you are paying for, and nothing else. After all, these things, particularly the large ones (like silver statues) are heavier and cost more, and you wouldn’t want anything less than what you are paying for!
When you buy jewelry, you want the .925 quality, also called sterling silver. In that case the piece MUST be stamped in the back or in a not-so-obvious spot (so as to not spoil the beauty of the piece) as proof of its quality. The stamp can either be “.925”, or a small eagle head, or say “sterling”. The above is required by Mexican law to make sure the buyers do get what they are paying for. If it does not have one of the above marks or stamps, it is not sterling silver.
The .925 comes from the amount of silver in the alloy: out of 1000 parts, 925 are silver. Same thing would be for the .950 grade: 950 parts of silver every 1000 parts in the alloy. The other metal has traditionally been copper, 75 parts of it in the case of sterling silver, or just 50 in the higher .950 grade. This higher grade will also be stamped in the same place the .925 would, but saying .950.
You can also find beautiful jewelry which is not sterling (or .925), and it is real nice, too, only you should be aware of the fact that it is not sterling silver and it will either be made of alpaca (also known as nickel silver or German silver) in which case it should be stamped “alpaca”. The jewelry could even be made of copper or another metal, and then electroplated -covered- with a very thin layer of silver, in which case it should be stamped “plateado”.
In other words, each piece must be marked depending on what material was used in its manufacturing and, of course, if sterling silver is inexpensive in Taxco, alpaca or silver plated pieces will be even less expensive because they have less silver, which is the expensive metal in these cases.
When buying holloware, you should be aware of the fact that, with international silver prices so high nowadays, it is most likely you will only find silver plated -plateado- pieces, and not pieces that are made 100% of sterling silver. It is in this case when you most want to make sure you know what you are buying, as holloware is costly, since it takes a lot of metal, artisan work and time to make the beautiful pieces, whether made of silver or another metal. You can find sterling silver holloware, but it is rare.
Hopefully you now have a better idea of how to identify the quality of the pieces you see, and will be more confident about it.