If you can laminate counter tops you should be able to do Corian assembly yourself.
It's not rocket science.
Your supplier should help sponsor classes for certification, which is required to be able to purchase the supplies. You probably already have most of the needed tools. Might need a bunch more clamps, but I doubt it.
I'll bet you could buy the material and do it yourself for a third of the cost of having it done. If not less.