While there may certainly be low quality cheap DJs, there is also some very good ones who either decide to stay at the lower end, or don't know the right way to move from there. You risk things turning against you if you use the simple stereotype.
A better response, IMO, would be to highlight things that would intrinsically add cost (redundancy in gear, ability to get an equal replacement, liability coverage, etc.) and make the client wonder why someone might not be charging enough.
Either way, devolving to price has many pitfalls.
Pricewise, I am in the middle of my market. I started doing bridal shows three years ago, and there are a lot of displays that give off sort of a bait and switch image by my competitors.
I'll actually offer to price match any direct competitor or do a "subjective" apples to apples comparison on any other package a couple is assessing. Honestly, I tell couples not to even show me the name of the person or service until I have done the comparison so it does not look like I am tearing down someone. If they are getting the same as what my company can offer, I will consider that person too a direct competitor and match that price.
That being said, here is what my expectation would be to consider that person a direct competitor:
Business Operations:
-Registered with the secretary of state (a legitimate company with a point of contact listed - there are too many fly by night places that close up shop overnight)
-Liability insurance
-Written or electronic contracts used
-Written or electronic estimate provided with an "Out-the-door" price which includes any and all charges (transportation/OT etc.)
-Packages should be similar (e.g. includes similar amounts of time, lights etc.)
-In-person consult and online planning tools offered
-Price presented must be a regular price or promotion and not a one-time offer (e.g. someone won $500 off because of a drawing at a bridal show or something)
Performers:
-Wedding performers have a minimum of one decade experience and can coordinate the evening and emcee the event
-Small multi-op service where you get to talk to your actual performer, yet others are available in an emergency situation
-Performers should be able to mix and/or beatmatch (not using itunes, Youtube or Windows Media Player)
Equipment:
-Professional (not pro-sumer) equipment by reputable brands such as QSC, EV, Pioneer, Bose and Denon or equivalent (Not to bash brands but if the other person has the $99 Harbinger or Gemini Powered speakers - I can't compete when I am using speakers that cost at least $600/pc. If the other company is using Yamaha, Peavey etc. I'll look at the line and specs)
-Any tops should be pole mounted
-Two true diversity wireless microphones
-On-site equipment backup and all special songs backed up to a second source
Music:
-Computerized music library with legally obtained music and clean versions available of all popular selections
-Critical selections should be stored locally and not "streamed"
-4g hotspot to procure anything not in the library
By the time I get to the end of the list, that normally weeds out most bottom feeders and many fellow part-timers, or generates some serious questions/concerns. To my recollection, there was only one or two times I actually had to exercise this since I raised my prices in 2013.
I normally work out to be $200-$800 cheaper than some of the large multiop, fulltime companies that employ salespeople etc. The tradeoff by booking with me is there may be a slight delay in communication at times (as I work M-F), I am not available to meet during business days and I don't have a fancy office you can come to. I am upfront about this.
If the packages or something about the companies are not the same, I'll explain the differences as best I can and sometimes offer something extra (ceremony system, monogram, waive overtime or similar). There have been a few awkward times where I have had to explain how someone else has better equipment or is offering something I can't provide, but 98% of the time they are priced higher.