It's one of the 1980s ones, right?
I would guess somewhere around the price of a 1970s Sprint in similar condition.
They're basically a 1970s Sprint, with some weird changes. A giant glove box, round tail, and volcano-looking speedo.
The US market ones had the same CEV turn signals and taillight as 1970s Vespas.
Probably depends on the condition, but wild guess: in decent shape maybe $2500? Maybe more if it's all original and pristine. That's if it was originally imported to the US, and lived a similar life to US bikes (like ridden 3000 miles and left in a garage for decades).
They made a lot of those in India, but few made it to the US.