Though I am very warry of competition, I don't worry about what they are charging. Yes, there are some detailers who do a cheapo crap detail for $75 in my area.
I always quote a job at what I think its worth. Then if a customer says they got a qoute for $75, I say "well I have a $75 detail package too, would you like for me to tell you the difference between the $75 detail and the $175 detail?" Immediately and without saying any more, my business is competetive. I then tell them about the detail packages and let them decide. Chances are the customer didn't find out or doesn't really know what is involved in the competitions $75 detail and you will look like a pro when you educate the customer. Either way, I try to book every deal that calls me. Never pass up an opportunity to get a new customer! Once you're infront of them, Upsell, Upsell, Upsell!
For $75: wash and wax (no polish, no clay, no nothing), dress exterior
vac, spot clean carpets (no extraction), clean and dress surfaces
(yes this makes me like the other cheapo crappo detailers, the difference is that I tell the customer what is recommended, if they decide they want the cheapo detail, then the customer is the cheapskate and I end up making what I am worth, $75 for an 1.5 hour detail)