Playing the Co-op Condo Conversion Game?

You mean "rental will turn condo", right?

Depends on whether the apartment's rent-stabilized. If so, then yes, the sponsor would have to either (a) buy you out, or (b) entice you to buy.

The insider discount will depend on the market at the time, how well the tenants' association negotiates, etc. Even with the discount, you may be better off remaining as a tenant.

If you're a market-rate tenant, then the sponsor might just wait for your lease to end, not renew it, warehouse it empty until conversion, then sell to an outsider. It might be, though, that the sponsor has to offer the same terms to any kind of bona-fide tenant. I'd check out the docs at the Attorney General's website.