There is no simple formula, you will have to write a VBA script to loop through all the lines, select the course AND the race number starting from race one and then sort that group by price. If you use a select statement you can include the sort function into it.

You will need a double loop, first for the course, and an inner loop for the race number.

I haven't used VBA for many years, so I cant help you with that, the closest I can come with is VB which is similar, but I think someone out there is an Excel guru and will be faster, Chrome P maybe?