price comparison-

The more you buy from a given supplier , the cheaper they get.
If a seller only buys 50 , he pays more per unit than a seller buying 500.
It also may be an obsolete engine, ( by 2014 standards )


After looking at the sight:
Older style motor kit.
For small tube bicycle frame.
Center fire head.
1st gen carb.
Steel intake.
May be a bushing motor.
Etc. etc. etc.