Personally I tend to think that insurance is a negative expected value proposition because the insurance company has their expenses and profit above and beyond the claims they pay.
So I have tried to self insure for as much as I could for as long as I could. I have never carried roadside assistance coverage. I haven't had comprehensive or collision for at least 12 years. The deductible on my home insurance is $10K.
The way I would look at it though, for this sort of thing is to take the difference in monthly premium at the various deductible levels and do a simple break even analysis. If comp and collision with a $250 deductible is $50 a month and comp and collision with a $1000 deductible is $25 a month, then that means a $750 difference in deductible for a $25 monthly fee. $750 / $25 is 30 months - does a comp or collision claim above $1000 come along that often on average? If not, then switch to the higher deductible. If so, maybe look at taking some driving classes :-)
I think temperment comes into play also. Mathematically coming out ahead isn't as valuable if you or your wife are stressed out about it all the time or if you get emotional having to write a $1000 check when it could have been $250. Partly for this reason my kids and I are on Silver level coverage even though Bronze is probably more cost effective - their mother likes it that way and even though she and I are no longer married there is more value to her in being at the Silver level than to me in being at the Bronze level.
After doing this across all kinds of insurance coverage, and not having had any claims in the past 12 years, I've built up quite a bit of buffer, so now I'm playing with house money as it were. I do think there is also a slight effect in me being more careful because I'd have to pay for things (my health, my car, my house) if I break them.
Good luck!
