I've struggled with this same issue, as some of you well know. On the one hand you have cheap tourist versions more suited for display on the wall in some Orientalist's house than ritual practice. On the other you have charlatans charging exorbitant prices for the genuine article, which you still can't be sure of in all honesty.
Best bet is to deal with the instrument maker personally. I accompanied a friend when she did this in Dharamshala, and can ask her about who her source was. Obviously this is much easier to do in Tibetan communities overseas, but it should still be possible where there is a strong exile community (Charlottesville, VA comes to mind).
Alternatively, your friend could always ask if there are any Kusali Chöd practices within her lineage. Kusali, as I understand it at least, is practice done without any instruments and is all visualization.
Karma Chagme talks about such pithy practices in his Mountain Dharma
. In the version published by KTD with Khenpo Karthar Rinpoche's commentary, it's found in volume 2. I also believe that the Namchö Kusali done in Palyul is sans accoutrements. Willing to bet that there are Kusali done in all schools, if not all lineages. As mentioned previously, Chöd was often done by wandering practitioners.
If she's set on getting the ritual instruments, or was told to get them by her lama, there are a few options that don't cost an arm and a leg (all pun intended!)
The most reasonably priced kangling I've seen online is the copper one sold by DharmaStuff.com, which was created by Drikung Ontul Rinpoche to help meet the needs of his students. Have to imagine that they were encountering the same issues. Also, the proceeds go towards the creation of a Jowo in Boston, so it's helping fund a good cause, not lining someone's greedy pockets and jeopardizing samaya.http://dharmastuff.com/shop/article_TDCC/Kangling-(thigh-bone-trumpet).html?sessid=YWxBPdkiUPEKCZkrnOsk0NL5gTB8jEMqm1zYqqFjwYsrXzgn2tp6ukkrlivW8NHZ&shop_param=cid%3D3%26aid%3DTDCC%26
"The Sutras, Tantras, and Philosophical Scriptures are great in number. However life is short, and intelligence is limited, so it's hard to cover them completely. You may know a lot, but if you don't put it into practice, it's like dying of thirst on the shore of a great lake. Likewise, it happens that a common corpse is found in the bed of a great scholar." ~ Karma Chagme དྲིན་ཆེན་རྗེ་བཙུན་བླ་མ་མཁས་གྲུབ་ཀརྨ་ཆགས་མེད་རཱ་ག་ཨ་སྱས་མཁྱེན་ནོ།