Have I 'spent' my negotiating power on higher salary, or can I further negotiate the TT startup offer? I have an R1 offer in Engineering. The department and Dean, per my request, have offered me a very good salary competitive with my competing industry offers, as well as excellent lab space.  However, the startup package is lacking. Equipment is 50% what I hoped for, travel budget is 25%, and they fund only one grad student for 2 years.  This will slow my lab-building.

As a note, I was asked to apply, but was planning to move to an industry position. The result was an early assurance that a competitive salary offer could be made.  The offer just arrived. I have, technically, not yet begun negotiating.

The question: have I spent my capital on this higher salary, or is the salary a reason to think I should be able to negotiate further?  Any suggestions on how to approach this in terms of tone/strategy?

Update: because salary was a precondition of agreeing to apply, negotiating was indeed expected, and successful. My tone in negotiating was all about thanking them while identifying what more I needed to succeed.

UPDATE: I negotiated beyond salary, successfully. The high salary was brought up in that process, and I nonetheless substantially increased my non-salary offer.
In general, departments don't like extended negotiations with candidates for faculty positions.  In some cases, candidates use this as a way to extend the time that they have to consider an offer so that they can interview for other positions and obtain other offers.  If a candidate ends up not taking the job after an extended negotiation then it may be too late to get the next candidate on the list.

There are differences between salary and startup packages:  

In negotiating faculty offers the budget that pays for faculty salary is often different from the budget that pays for the startup package.  In any case, the startup package is one-time money rather than a permanent salary.  Thus if the one-time money is available it might be easier to come up with $100K more of startup funds than $10K per year of salary. 

At public institutions, faculty salaries are often public information while at private universities these are generally secret.  At public institutions, it can upset other faculty members if a new assistant professor is hired in at a much higher than normal salary.  Large differences in salary are much more common at private institutions.  

It appears that the OP made his salary needs clear before agreeing to interview but that the startup package was not discussed before the interview.  Furthermore, the offer that he has received is the first offer from the institution.  Under those circumstances, it would be quite normal to negotiate the startup package.