It's a bowling ball. I assume you are aware of the dimensions and weight of those things?
Unless you got a firm quote before bidding the seller is actually entitled to charge whatever he thinks fair. There is not price to Canada in the listing that I could find. Domestic (US) shipping seems to be $20 which strikes me as low.
I tend to assume that any seller who asks for Best Offers is not too knowledgeable about the value of his items and by extension about the cost of shipping.
You can't force him to ship, although you can make things uncomfortable. $75 strikes me as a very good price and $150 rather high for a used ball.
I'd suggest asking for a Mutual Cancellation and leaving no feedback. It just didn't work out. Don't get your knickers in a twist.
