It depends greatly on what you are getting for your 5%. There may be "great marketing and mailers" - but in the age of the interwebs mailers brings in zero buyers. This realtor may appear to be a "high volume area expert" - but some "high volume area experts" have sold 1 home a quarter instead of 3-4 each month as true high producers do. I'd comb the agents on-line data for recent sales presentations. Do their $3-4m listing have iPhone or professional photos? I've seen some $10m listings with 8 photos - one of which is a laundry area! Blegh. $4m homes do require a significantly higher buyer contact network compared to a realtor who sells $1-$2m homes day in day out. Has this 5% Agent sold 5 $4m resale homes in the last 12 months? That would be Question 1 before I committed to that high of a fee.
There are some needs a seller has that can justify a 5% list - privacy issues, unique legal questions to overcome, needing a very high level of hand holding during the sales process as you see in a relocation. If a seller needs these "benefits" that should come from a 5% list fee, then OK. Its reasonable for that seller. If you can't find a tangible benefit that your sales process must have, does it make sense to pay for it? 5% is the old 6% repackaged as a "great deal for you". 4% has become the norm, unless as noted a Redfin or flat fee sale agreement comes into play. Of course you get what you are willing to pay for, but overpaying at 5% seems difficult to support considering a homeowners many selling options today.