I have had mixed success with high end boots. It seems to me that no mater what you buy, they last about a season and a half, especially if you do any bush whacking. For that reason, for the past decade I have been using lower end boots by Hodgman and Dan Bailey. You can buy a very functional, comfortable pair of breathables from Hodgman for about $60 on sale. They will not breathe like a Simms, but they are fine 95% of the time. Layered in the winter, they keep me warm just fine, in summer, they are cool.
Alternatively, the Dan Bailey Barebones are an excellent find, for about $120. They are nicely made and fit a little better than the Hodgman. They also have the nice side straps to help the fit.
I just don't feel it's worth spending more than that. Save that money for a new rod.