The comment,
"The what, $100/year or so interest charge is the 'rent' on the $20k loan. Use their money, not my money - and get the tractor NOW, not years from now. Well worth the $100 'extra' the interest is gonna be."
is my main point in this thread.
If you actually run hard numbers (see my first post) the cost of financing is a staggering high amount. It can amount to $1,000's of dollars per year in finance charges, lost investment opportunity (paying interest as opposed to earning it), etc. not the ~$100/year as you are stating.
Now, having said that, my analysis also ignores intangibles such as the satisfaction of using the tractor, ability to get projects done, etc. As many have pointed out, that is not an insignificant consideration.
The point at which everything becomes an acceptable "cost" will clearly be different for each person, and is a largely personal decision with many factors to consider. Again, with many great examples in this thread.
However, I think the true financial impact on the wallet is often overlooked, or even downplayed, without developing a complete picture of the financial ramifications.
That is, it's easy to "buy into" (pun intended

) the salesman speak of "hey, this nicer tractor is only an extra $50/month on the loan," which is really just a clever sales trick to obfuscate the true cost.