The principals at Artvest have done a little homework on the Spring Contemporary art sales. You can find their full analysis of the sales and the CAGR (Compound Annual Growth Rates) and IRR (Internal Rate of Return) generated for many of the works on their site. Here are the top 5 lots in terms of return and the bottom 5 lots. The entire list is available as a pdf downloadable on the Artvest site:
Top 5 Works