The bushings are a) bonded to the a-arms, and b) not cylindrical. (So, no, not replaceable.)
A-arms from BAT are $175 each for horizontal (early) bush types, and about $114 and $132 from Bill Jenkins. Later, vertical-bush types are considerably less. I'd think you'd be in under $200 for parts, so $500 for labor? Seems a bit steep...