Jedediah - it's your money and your decision of course.
A friend who is also a member of this forum and an avid collector Bizen Den searched for a blade from this smith for several years before he got one that was worth it
Study Saburo Kunimune thoroughly and learn what you don't want on a blade from him
Spending money is the easiest thing in the world - the market offers thousands of ways to do it.
However, when it comes time to sell, you will have a very hard time selling such a blade to collectors because:
1. the number of people who can spend that amount on a blade is limited
2. these people usually know and understand what they are looking for
This is just friendly advice
Don't rush
I agree, right now I'm scouting the current market to see what's available, what has been sold and some model examples by kunimune. So far I have found 3 for sale and dozen other examples by him. One seems to fit the standard I'm looking(though very few pictures of the blade)for but I'll wait to see if anymore better comes to the market.
https://www.nihonto.us/BIZEN SABURO KUNIMUNE.htm
This is the one I'm currently looking at.
Not to sure about the seller though