$200 to $300 if the bar, speaker and retaining bands are not dented up; everything works (inlcuding the speaker); the domes are not cracked, chipped or crazed; it has mounting legs/feet; it has the black Visibar endcaps; and legible manufacturing tags. I recently restored one to near mint condition for another collector for $475, but it included several NOS parts. I usually pay between $80 and $120 for those in average condition, so probably wouldn't go above $250 for the one you're being offered.
Good luck!
