Taking up space: start-up package

I was recently offered a faculty position at an excellent public university (R1). I am being given all kinds of very helpful advice and information as I prepare my start-up package prior to my upcoming second visit and negotiations. The common theme of the advice I am receiving from all sources is "ask for what you need to be successful". Seems easy, but I am having a hard time with this. I have created a detailed document (including several tables) outlining my start-up budget. I know the total amount is significantly higher (by about 40%) than the average start-up package for new faculty in comparable departments. There is one reason my start-up is so high: one instrument I think I need is very expensive, it's cost accounts for roughly 40% of my total start-up budget.
It really freaks me out to ask for so much, hence the issue of taking up space. Obviously the space I am referring to here is not physical, rather it refers to asking for a lot of department resources. All my mentors (if it matters to anyone they are all male in this case), have advised me to literally not shy away and to ask for everything, despite the high grand total. Why am I freaked out? First, I do not want to create a situation where I start a new position and find myself resented by other faculty because I asked for (and received) way more $$ than they did. Secondly, and a bigger fear for me, what if my research ideas for this $$ instrument do not work? I know I can do a lot of my "bread-n-butter" low-hanging fruit type research on this instrument, but the "accessory" that I want which would allow me to pursue bigger, riskier questions is what makes it cost so much. What if this area of my research does not pan out? Have I wasted department resources that could have been better spent on something/someone else? That is what my fears boils down to I think.
So my start-up document currently contains two options: option 1 includes everything I want and has a huge grand total, while option two does not include the fancy, $ "accessory" and hence is a much more reasonable start-up amount. I know I should not give someone in charge two options, one much cheaper than the other.. I just do not want to seem unreasonable. My former postdoc advisor knows my research ideas and while he acknowledges they may be risky, he doesn't think they are impossible or totally crazy and he has advised me to ask for the grand total and not to be "wishy-washy" about it. He knows I have a tendency to start talking myself or my needs down as soon as I ask for something.
I think it just boils down to that fact that I do not want to be perceived as unreasonable, and I do not want to make promises that I may be unlikely to deliver (e.g. success on riskier research questions with fancy instrument).
I guess the worst thing that can happen is they say no to my grand total and I figure it out from there right??