u/DeepestWaters

• AR15Discounts.com: $140 or 3-pack for $130 ea.
• DirtyBirdUSA.com: $130 (sister site of AR15Discounts)

They've been out of stock for months, selling way above MSRP on gunbroker. Especially good timing for VA and RI, with sales bans closing in fast. Black only for now, other colors potentially coming.

No affiliation with the shops but they're legit.

For the uninitiated: lower receivers are the serialized "assault weapon" in the eyes of the law, but are just a rectangular frame the rest gets attached to. The M4E1 is made by Aero Precision, widely considered an excellent quality/cost value.