Most speakers aren't designed to be field-reconed, including Infinitys. (Boston Acoustic makes some competition-grade subs that are modular and can be field-stripped.)
The average price for a reconing is somewhere in the $50-75 range IIRC, at least for home speakers of that size. If you're worried about shops being qualified to do it, you could instead send it to Infinity for repair -- it may cost a little more, but at least you'd have the peace of mind knowing that the job would get done properly.
And, it needs to be said: Regardless of whether you fix your sub or buy a whole new one, invest in a grill, particularly one of those mesh ones.
The average price for a reconing is somewhere in the $50-75 range IIRC, at least for home speakers of that size. If you're worried about shops being qualified to do it, you could instead send it to Infinity for repair -- it may cost a little more, but at least you'd have the peace of mind knowing that the job would get done properly.
And, it needs to be said: Regardless of whether you fix your sub or buy a whole new one, invest in a grill, particularly one of those mesh ones.