The most persistent "salesman" ever...

I will try to keep this simple. I'm too exhausted to write much. How do I withstand the constant barrage of ideas and brainstorms, and all of the relentless negotiation he pursues with me to try to get me to agree that it, (whatever "it" might be) is a great idea, and i should be on board.

Eg. (1 of 10's or 100's in a week) Should I just patronize him after 30 minutes of hearing the benefits of an $800 microwave we won't buy in 5 years when we redo our kitchen? I feel like I have to say, "sure honey, sounds fabulous." instead of "not interested" or "maybe we could talk about this later, or when it's more relevant to our immediate plans...we need to get DJ ready for daycare and both of us ready for work right now." The latter, more honest statement, incurs the "teenager as salesman" behavior until we are running late and my irritation feels like my blood boiling. I try so hard to get him to just drop it, then sometimes I lose it say something like "leave me alone!" or worse.