You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Nikola_Tesla

Context:
The mid 1890s saw the conglomerate General Electric, backed by financier J. P. Morgan, involved in takeover attempts and patent battles with Westinghouse Electric. Although a patent-sharing agreement was signed between the two companies in 1896 Westinghouse was still cash-strapped from the financial warfare. To secure further loans, Westinghouse was forced to revisit Tesla's AC patent, which bankers considered a financial strain on the company (at that point Westinghouse had paid out an estimated $200,000 in licenses and royalties to Tesla, Brown, and Peck). In 1897, Westinghouse explained his financial difficulties to Tesla in stark terms, saying that if things continue the way they were he would no longer be in control of Westinghouse Electric and Tesla would have to "deal with the bankers" to try to collect future royalties. Westinghouse convinced Tesla to release his company from the licensing agreement over Tesla's AC patents in exchange for Westinghouse Electric purchasing the patents for a lump sum payment of $216,000; this provided Westinghouse a break from what, due to alternating current's rapid gain in popularity, had turned out to be an overly generous $2.50 per AC horsepower royalty.

Question:
What was the overly generous royalty amount that Tesla had been receiving? 

$2.50 per AC horsepower royalty