It was a option available for a shorter barrel as he said he'd pursue the 590 route...
And yes I've sold multiple receivers for $250 within hours of posting .....
A maverick 88 is a POS cost cutting gun that takes the 500 platform as cheap as it can come and they sell for around $330+ tax now do about $360 all in for a single barrel option...the stock is super thin, the foregrip is the cheap single mold that isn't interchangeable. It has a completely different trigger mechanism and safety design. The 500 has the entire safety setup ontop and that alone goes for $50 let alone the entire receiver. Bolt and carriers $60-$80. Trigger group typically $75-$100. Cartidge stop,interuptor,ejector average $15-$20, shell elevator $20-$25. Let alone the receiver housing typically $60-75. So add that up and if you want to build a new gun and not deal with a stock or a old 28" rib fixed barrel you don't want then Just buy a receiver and go from there . Those priced are ee prices even. Half of those you can't even order as there factory only parts, a bolt and carrier new from a dealer is well over $125 and a trigger group pushes $200......