I have a few things to say about the search numbers, but it's not just the numbers that make this domain so valuable. It's the fact that this is a large industry category. If I need some parts to fix a toilet, or water faucet, this may be one of the searches I do.
"Plumbing Supplies" broad search gets 165,000
"Plumbing Supplies" phrase search gets 165,000
But "Plumbing Supplies" exact search gets 49,500
Notice that unlike most keywords, the phrase search is the same number as broad search. What does this mean?
Well, broad match is when the words are used in a search query, in any order with or without any other words, at least this is how it is described in AdWords.
Phrase match is when the words are used together in the same order, but also with one or more other words. This number is normally smaller than broad match, because in broad match there should be some people who search for "supplies plumbing".
The numbers are clearly rounded and not exact, but it is odd that they are the same.
My question is if the exact search numbers are included in the broad match or not? In AdWords, a broad match bid CAN match an exact match keyword phrase but is more likely to do so if an advertiser specifies an exact match bid. The point is that for advertisers the broad match can cover everything, but I think maybe for keyword research these numbers should be treated differently.
For a domain, I feel exact match is the most significant thing for a domain, and not so much phrase match, and even less so broad match. For domain parking you don't have much to work with to optimize your content (in many cases) so the keywords in the domain are much more important. When you have a full site or a lot of content, your SEO can give you more advantage than just the keywords in a domain. The only possible exception would be if you get many, many links to your domain but most parking providers don't allow you to do that.
Summary: Broad match numbers are nice, but most people consider exact match numbers as being the most meaningful.