I need to start building microwave tubes. We need an MRP system with
at least 1000 items in item master. 25 or more levels on the bill of
materials.  Need ability to record quotes at different volumes and
multiple vendors.  NRE's (Non-recurring expenses) recorded separately
on all the quotes.  Costed BOM.  Generate PO's and purchases. 
Accounting A/P, A/R and G/L optional, mySQL preferred.

Please provide at least one and preferable three packages that meet
the requirements stated above.

As I am not familiar with these terms, I would suggest you search "MRP
package sharware" (without quotation marks) for a shareware list as
that is usually much less expensive.  Good luck.

MRP stands for Manufacturing Resource Planning (I think).  In any
event, it is a system used to help manufacturers plan and control the
manufacturing process.  BOM stands for Bill of Materials.  I did a
search for MRP under shareware and came up with nothing.  That is why
I am offering to pay money to someone who can find a suitable
solution.