That's a heck of a good price even if it is a refurb. I paid close to $600.00 new for mine and it had 5.0 batteries.
What is the warranty like for a refurb?
I believe it has a full factory warranty , same if bought as new.
This is what is on the CPO website for Milwaukee reconditioned tools
The Milwaukee Reconditioned Product Limited Warranty
Every MILWAUKEE RECONDITIONED product is warranted to be free from defects in material and workmanship. Subject to certain exceptions, MILWAUKEE will repair or replace any part on a reconditioned product which, after examination, is determined by MILWAUKEE to be defective in material or workmanship for a period of one (1) year after the date of purchase. Return the reconditioned product and a copy of proof of purchase to a MILWAUKEE factory Service /Sales Support Branch location or MILWAUKEE Authorized Service Station, freight prepaid and insured. This warranty does not apply to damage that MILWAUKEE determines to be from repairs made or attempted by anyone other than MILWAUKEE authorized personnel, misuse, alterations, abuse, normal wear and tear, lack of maintenance, or accidents. THIS WARRANTY SUPERSEDES ANY PRIOR OR OTHER WARRANTIES CONTAINED IN ANY OPERATOR'S MANUAL OR OTHER DOCUMENTS RELATING TO THIS PRODUCT. THIS IS THE ONLY WARRANTY APPLICABLE TO THIS RECONDITIONED PRODUCT.
All reconditioned product is etched or stamped with the MONTH & YEAR in which it was reconditioned, along with an “R” - Recondition Designation and the reconditioning plant location designation.