How much does it cost?
It doesn`t matter, whatever it is, do it! Every single time! whatever the cost it`s nothing compared to the horrendous consequenses of non working, battery operated smoke detectors, in human life, as we`ve seen, as well as the financial cost to all involved(legal fees, fines, parents burying their kids...yuk).
The only question is, "Where can I find an electrician to do it?" and the answer is, any quliaifed electrician can do it. You`ll likely need to zip out some drywall here or there to make it happen, but in the grand scheme of things, a bit of mud and paint is just a cost of doing business.
I do renovations, and we just did a basement suite in a home. We made sure to have a hardwired detector, but as important, it needed to be outside ALL bedrooms in the house, and they must ALL be linked together according to the code. You need them to all go off if one does. That way the upstairs people aren`t sleeping away while there is a raging inferno beneath them, or vice versa.
As for the whole legal vs. illegal suite debate. Unfortunately municipalities still make people jump through a ton of hoops,(parking, neighbour permission, etc) so a lot of landlords will choose to avoid the risk of exposing their suites to the authorities, lest they be shut down.
Then as a result, we end up with hundreds of suites that violate the codes, mostly because the owners either never know the codes exist, or don`t take them seriously, which leads to the recent tragedy.
In all likelyhood, the person is not inherently evil, they just didn`t know they had a death trap on their hands, and they would never invite anyone to look at it from a safety angle, because they know the city would kill their cash flow.
IMO municipalities ought to have a grandfather clause. "If you`ve been operating a suite for X period of time, and no neighbours are complaining, we`ll come, look at it from a safety point of view, and help you get that aspect up to code, no questions asked." Lives would be saved.
Sorry...end of rant.
Keith