They ALL start like this. I sold my 9.6 IH #181 at an 8900% increase in price. (And I think your math is way off btw).
May 25 Superman Adventures #5 eBay Prices:
$95, $76.11, $137.50 (all include #4 and AC 835), $71 (from Ireland) and $89.99, $90, $85.99, $99.09, $74.99.
I used $1 for the early March price and $90 for the price on eBay on Sunday. The three sold listings for the book on March 22 went for $3.49, $0.91, and $1.49. If you average those prices, I guess it was a $2 book.
What were the bought/sold prices and timeline on your IH #181?
$.25 July 1975 to $2200.00 June 2002