Leroy has the price right.
Here in southern Minnesota no one wants to putz with a one row, and few bother picking any corn any more, so certianly under $100 around here. I bought 2 row 300 for $30 in great shape a decade ago, bought a 6A for $100 decages ago, and just got a 324 for $165. All 3 went right into the field, good condition. I would expect to pay scrap iron price for a one row picker around here.
In some areas 'out east' the one rowers bring over $1000.
Usually the one rows are older like the 6A, and are kinda slow - built for 100 bu corn, not 200 bu..... Good machines tho, & Agco supports them amazingly well for their age. You will pay for that support tho....