As has been mentioned, plated findings are acceptable accross the pricing spectrum.  The key is the quality of the plated findings.  If the plating comes off when just handling it...it's the cheap "junk" that has given a bad name to plated findings.  There are excellent platers that actually take pride in their products.  These higher-end platers usually only sell to distributors, stores, and possibly high-volume design houses.

To avoid any "issues" we only carry plated findings that are lead-free, nickel-free, and hypoallergenic.  I suggest that you check at the local bead stores in your area to get more information and help you learn more about the products.

I have had a lot of success using vermeil - gold plating over sterling silver.  I like it better than gold plating over brass and it is less expensive than gold fill.

I use mostly sterling, copper & brass.  Brass is a nice alternative to gold or gold filled as it has a great old fashioned gold look.  It's much cheaper and will not rub off over time.  Great for those long chain looks.  You have to be careful with copper.  Make sure it says pure copper, not plated.  

I have used plated and pewter as well.  They work well, but state what you are using always.  People will choose for themselves whether they want to pay less for the plated necklace or more for the sterling one.  It's good to have options in different price points, especially at craft shows.