I have two questions related to purchasing.
1. Is anyone working at an institution which has special provisions for
purchases made under grants and contracts?
2.  We have a $500 threshold on single purchases if they are to be
exempt from the bidding process.  The problem arises with respect to the
definition of what constitutes a single purchase.  Our purchasing
department's position is that if they receive two requisitions from the
same department or grant, each of which is under $500, if there is any
possible way to construe the as a single purchase, they will combine
them and put them out on bid.  For example, a PI submits a requisition
for laboratory glassware and a seperate requisition for chemical
reagents.  The purchasing agent combines these reqisitions using the
justification that both requisitions are for "laboratory supplies".
Consequently, the $500 threshold is exceeded(by $29) and they go through
the bidding process.  The PI gets upset--and you know the rest.  Does
anyone having any advise on dealing with kind of situation?