Charles,
I have -- had, rather -- the large set of Yarka's that were given to me as a gift. The large set, of which I can't remember if they contain 120 or 180 sticks, consists of duplicates of most of the colors. I believe you actually only get 80 different colors.
I used the Yarka for about a week and put them away. They are not the same as Winsor & Newton or Rembrandt -- I use both those brands daily. They are rather "dull" and contain many bits of paper-ripping/scoring binder. They are considered a very, very low end "student-type" pastel and I did not care for them at all. At best, I was considering using them for plein air studies this summer.
On many websites I've read that Yarka contain impurities -- never mix them with your good pastels -- and therefore I don't feel comfortable with endorsing these at all, even for students.
I gave mine away to an aspiring young artist who was thrilled to receive them

He's turning out some great work with those pastels and I'm happy to see them get used up.
I replaced my Yarka with a 96 Nupastel set, and this is one of the ones I would recommend to you.
If you are looking for a low-priced "professional" set (Nupastels are pretty much used by the majority of pastelists) that contains an extremely varied assortment of colors, then I highly recommend that check out the Nupastel 96 set. They retail from $46-$60 and are considered a "hard" pastel. As an aside, I don't find them all that "hard" unless you compare them to Sennelier and Schmincke.
Art Supply Warehouse currently has the best web going price for the 96 set Nupastel. The purchase also includes the pastel book
Pastel Painting Techniques by Guy Roddon (this book retails for $18.39 on Amazon.com). The book contains 17 pastel projects to get you started. It's a great book for persons wanting to get a "handle" on using pastels. I have it and have lent it to my young artist friend
The Nupastel set and book are selling for $47.99 at the ASW site. Here's the link:
http://www.aswsale.com/prisnup96col.html
You may also wish to consider purchasing a half stick 60 assortment of Rembrandts. Rembrandt is a fine way to get started and, again, many professional pastelists use them. ASW, once again, has one of the best prices on them. Here is the link:
<A HREF="http://www.pro-mall.com/cgi-bin/catalogs/webcart.pl?DISPAGE=3&CONFIG=aswexpress&RET=5&LOGIC =1&START=11&DOSEARCH=YES&FIRST_TIME=No&RCATS=PASTE LS/CRAYONS&OCATS=&FOUND=35&TOPPAG E=&CODE=129">Rembrandt 60 Assorted $34.97</A>
If you want to do your own research for pastel sets, I would suggest the following sites:
<A HREF="http://www.aswexpress.com">ASW Express</A>
<A HREF="http://www.aswsale.com">ASW Sale Site</A>
<A HREF="http://www.misterart.comt">MisterArt</A>
These sites tend to have fantastic sales and great prices on mid-range sets.
If you want to research more sites, I have a list of vendors who also sell open stock sets on my web site. Here's a link that opens directly to my vendor list:
http://roanstudio.com/cgi-bin/reviews/stars.pl
Most of the vendors have reviews and are rated on a scale of 1-5 stars. Both the reviews and ratings are done by my site visitors. I've only written reviews for a few of them.
I hope this helps and please post if you have any more questions!
Hugs!
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<FONT face="Script MT Bold"><FONT COLOR="#AB4835"><FONT size="5">Roan</FONT s></FONT c></FONT f>
<FONT COLOR="#8A1010">"Bu shoilleir a dhreach, 's bu luath
Shiubhal: Sith-fada b'e ainm." --</FONT c>
<FONT size="1">"Shining his coat, and speedy
His pace -- Si-Fada his name."
Si-Fada = "long pace"</FONT s>
RoanStudio.com <--- supply resources for pastelists!
[This message has been edited by Roan (edited March 27, 2001).]