I did mine ('01 X5) myself and it was VERY easy. Certainly can't imagine how the dealer could possibly justify $2000 in labor (or was that total cost?). I think I paid ~$650 for the hitch kit and maybe $30 for tools- I bought a set of Torx socket/bits in order to have the proper size Torx bit.

Any independent shop could do the install at a considerably lower labor rate than the dealer.