I posted a RFQ for Commercial Services on FBO. I receive four quotes that are acceptable. The prices came in $1,050,000, $1,075,000, $1,125,000 and $1,175,000. Programming only has $950,000 available for this project. Is it acceptable to go to the lowest quote I have and ask them to reduce their price to $950,000 and send them the PO if they agree? I am essentially counter offering their offer. Thoughts?