Conversation so far:
What was Seattle Slew's heritage?
Seattle Slew was a dark brown colt with a small white patch of hair by his left rear hoof bred by Ben S.
Castleman.
Did he show signs of his greatness early on?
CANNOTANSWER.
When was his first race?
CANNOTANSWER.
Who were his parents?
He was sired by Bold Reasoning who won the Jersey Derby and Withers Stakes in 1971.
Who was his mom?
His dam My Charmer went on to produce the 2000 Guineas winner Lomond and Seattle Dancer.
Are there any other interesting aspects about this article?
In partnership, they bought 13 prospects, including Seattle Slew, who was sold for $17,500 (equivalent to $80,000 in 2017).

Question: Who bought him for $17,500?
Self-contained rewrite: Who bought Seattle Slew for $17,500?