If you think you can't afford an induction range, you also can't afford to hire contractors to have your new ductwork put in and/or unborked.

Much as I hate to recommend Frigidaire for various reasons, the FCFI3083AS is I think the most economical freestanding 30" induction range on the market at the moment and has an MSRP of $1099. You can probably score one from some discount or independent appliance retailers (i.e. not Home Depot, Lowes, or Best Buy) for a little under a thousand.