Quality is subjective. As I said - if I wanted a super short name that meant gold in Spanish and I had some cash to invest then ORO.CO is a great name.
But it's all dependent on what you are after.
If I owned a business that was based on branding then "namestrategy.com" would be better than all your names because it is what I want.
This was actually recent purchase by a branding company. As an END USER they paid $3,333 for a name that is an almost perfect match for what they are selling.. "brandstrategy.com" is the only thing better imho...
I know this particular area because I was looking for a name for similar market segment and did a lot of investigation and looking around. Personally I liked BrandJive.com which is listed for $995 at Sedo but I was worried about Jive Software TM so I went for NameArt.com instead which fits my notion of what a branding site would be.
These are names that I would love to have.. and all under $1K.
A lot of what you can get is based on WHO is selling. The reason that some keywords are so expensive is because the seller can afford to hold. This is not always true. Some people can turn down $600,000, some people will freak out with an offer of $1000. The market is all over the place
Point is that someone like Rick Schwartz would have asked $50K for that name and probably got it but as it is.. NameStrategy went for $3k. It's a perfect brand name and it was WELL under $10K. As far as other examples? Its hard to know what you can get for $10K until you start offering money. I'm sure DNJournal has some you can find.
For ORO.CO? If I could stretch $10K to $22K I would have gone for Karat.com which I think is a better name. Twice the cost? Sure, but it has 5% of the risk in terms of resale right now.
Quality isn't about single keywords - often a single word isn't as effective as two words.
Gold.com isn't as good as Cash4Gold.com as an example. Sometimes the second word is needed to explain the name. The exception is when you are strictly talking about brands.
As an example: lawyers would rather have "LawyerName"Law.com than Lawyer.com in my opinion because their name is important to what they are selling.
I'm sure others will have fine examples for you.