There are 2 major categories of Oil Pastels: student grade and professional grade.
The most obvious difference between the two is price with student grades as low as US$0.14 per stick to artist grades around US$3.00 per stick.
In this photo, the Loew-Cornell are student grade at about US$0.14 each stick (sold in sets.)
The other two are mid-price artist grade.The Van Gogh sell for about US$0.60-$1.00 each stick. (sold in sets or Open Stock. Open stock means sold individually.)
Cray Pas makes 2 grades of oil pastels. The Expressionist (student grade) and the Specialist (artist grade, shown above.) The Specialists sell for about US$0.90-$1.80 each stick.
A high-price artist grade like Sennelier sells for about US$1.25-$3.00 per stick (sold in sets or Open Stock.) Price ranges are what I see them selling for today and the cost difference between regular price and sale price.
What causes the price difference between grades? The student grade can have more wax and less mineral oil holding the stick together. This higher wax content causes the stick to have a harder consistency. The student grade also can have less quality and quantity of pigment and possibly be less light-fast (this last I have not checked into.)
Within each grade, difference brands behave differently.
If a student grade is what your budget can afford, try a few different brands if you are not happy with the feel of the first brand you try.
