Hi,
If your page is ranked 450th in Google that could mean a variety of different things; Google considers the page to be low quality content, duplicate content, it has an algorithmic penalty, it's not authoritative enough, or else it's simply irrelevant to the search phrase you're attempting to rank for.
It would be hard to say exactly what the problem is without seeing the page, but from what you say it sounds like a duplicate content issue. If this is one of a large number of duplicate pages then that could also contribute to Google's perception of your site as being low quality.
There are a few things you can do to try and correct the issue:
If you have 3 different pages each selling the same boots to three different places.. eg "Leather boots London".. "Leather Boots Los Angeles" and "Leather Boots NY" - then, like you suggested, you will need more than a change of place names to distinguish between the pages.
Try changing more on the page. Meta Titles, Meta Descriptions, Alt Tags & titles on images & unique copy - the longer the copy the greater the opportunity you will have to make it unique.
Linking between pages on your own site with descriptive anchor text is very important for helping Google to identify what the pages are about. Have a look at your site as a whole and have a think about your deep linking strategy.
Finally, Rel=canonicle or 301 redirect any similar or duplicate pages which you do not intend to correct and do not intend to rank with.
Alternatively, to try and determine if it's a separate, low quality issue, ask some of these questions:
How many ads are on the page? How many hyperlinks are on the page? Does the page look spammy - spelling mistakes, weird grammar? How long is the copy - substantial and factual or brief and lacking any specific detail?
However, the page being of low quality does not rule out the possibility of a duplicate content problem.
EDIT: If it's a Dup Content issue then what Alan said would be a far simpler solution!