Keywords with numbers...

Let's say, hypothetically, I found that keyword 1 has 45k exact monthly searches, and the exact domain with keyword1 was the company that owned it, but the domain keywordone was available...

How big of an impact would it be to spell out 'one' over using '1' ?

(be gentle I'm noobish)

ugh - scratch that - I am up waaay to late. Didn't catch the 'premium domain' wording and the $3k price...

moving on..

I'm actually still interested in knowing this for future reference

There is no big impact on anything.

If you don't have the rankings, the visitors, and the monetization of the website (making money), then the site is not worth much.

If you are referring to can a site with "one" at the end help you rank well, the answer is YES if you have enough backlinks. If you have Keyword1.com and still have lots of backlinks you will rank well also.

It's 80% backlinks, 10% domain name & onpage optimization (if you have keyword in domain & h1 title tags you rank better), 5% content, 5% domain age.