I generally associate respectable-quality AR-15s with a $1,000-$2,000 price tag.
Colt has bid less than $700 on contract pricing to the government. That means they are still making their profit on the merchandise - what is different is that it's a direct sale, not thru a chain of distributors and local gun shops. Each of them add their own profit that has nothing to do with any added value as a firearm.
Since one of the criteria was "affordable," then contemplating the S&W or even a Branded used AR15 is then logically feasible. For $2000 a pretty high end Noveske could be built, but it's very arguable that you are buying any increased reliability. What you get is a name and a marketed reputation.
A reputation exists for the Winchester, too. Pre 64, post 64, then add different ejection patterns, a side bolt safety, etc. The more it was changed, the lower sales dropped. There is a direct cause and effect there. Now you can't buy one at all that is US made, and the Japanese owners market them for over $1200.
Affordable? You could get two S&W AR15's. And the slick side upper is actually more traditional than the modernized safeties on the Miroku made lever guns.
Choosing a traditional steel and wood gun is up to you, the issue is how the specs are being interpreted. Some of us see it as more a matter of what is available on the entire market, not a limited selection of a few older designs that are fading away. Since one of the stated purposes was defense, then it follows that the best choice would be one that actually has defended America. That leaves the AR15, Winchester lever, and Remington 700 in that specific order as they match up to the specific requirements outlined.
That is the better decision if logic is involved, but plenty of us choose based on emotion, and there's no accounting for love.