You can find the prices for the different licensing of Unity at the online store.
At present, the prices are:
Unity 3 = $0
Unity 3 Pro = $1500
Unity iOS += $400
Unity iOS Pro += $1500 (Requires Pro)
Unity Android pro += $1500 (Requires Pro)
Unity Asset Server += $500 (Requires Pro)
for other pricing options, please contact sales@unity3d.com
For each purchase of Unity Pro, it will cost you $1500.For your purchase of the Unity Asset Server, it will cost you $500. For n machines with Unity Pro and 1 asset server license, the total is $1500 * n + $500.
The only mention of royalties in the EULA is:
The standalone runtime may be redistributed royalty free, as long as it is produced using a licensed installation of the Software. Copyright notices from Unity Technologies A/S and NVIDIA Corporation may not be removed from the standalone runtime. The Unity Web Plugin may only be distributed by Unity Technologies A/S
which clearly states "royalty free".
The licensing restrictions as stated in the EULA are:
(a) Unity Pro may be licensed by any company, educational institution, incorporated entity, or individual.
(b) Unity (free version) may not be licensed and used by companies, educational institution or incorporated entities that had a turnover in excess of US$100,000 in their last fiscal year.
(c) Discounted academic versions of Unity or Unity Pro may only be licensed by educational institutions for use by their students and staff. The license is granted for learning purposes and may not be used for publishing commercial content.
(d) A company, educational institution, incorporated entity, or individual may not license both Unity Pro and Unity at the same time.
I have contacted sales in the past and never had any issues and had only prompt replies. Is it perhaps that you sent to the wrong addressee or that your question was phrased in such a way that they could not answer it?