I run across this often. Have a client who insists golfers still love the 7K par 72 course and asks me to go to great lengths (pun intended) to boost yardage while renovating. What's funny is he claims to have loads of stats that prove him right, but never has showed them to me. When I googled 7000 yard golf courses exactly one article came up.....mine from about ten years ago, basically parroting what most here would say (yes, part of the reason I participate here is to mine article ideas...you try writing one every month for a dozen years!)
The thing I keep thinking about is when my courses have hosted regional tourneys, like Sand Creek Station and the last Mid Am, although it has back tee yards of 7.200, when the wind blew, they played at 6750 one day, and never exceeded 7K to protect the lower half of the field. Basically, unless you will certainly host the PGA tour, those tees rarely get used (I am presuming TD's course is coastal and has wind here)
I went through the exercise on a renovation -
Re-measure from 2 yards from the back of the tees, as most state golf associations will accept - nearly free, but print new scorecards, etc.
Add small back tees, no more than 20 x 20 (and maybe 15 x 15, given no one really uses them) at $10-20K, contractor prices, depending on where it is and how many you do. Came out to about $900 per yard.
Reroute holes and/or reposition greens at 100K plus per coy. Came out to about $9000 per yard.
For Tom's new course, the math would be different, basically divide length by 23 yards (sprinkler spacing,) times 2 or 3 rows, times the average $1500 or whatever per head. Add in a few acres of grassing and the cost probably wouldn't be as drastic new.
Obviously, there is no real way to figure out just how much, if any, of your play comes from each yard. $9000 per 300 yards is $2.7M, or $165K at low interest rates. For argument, you need only 1650 rounds if you net $100 per golfer, which is possible. For a muni course, where even a lower percentage play the back tees, and which might get $50 per round, getting over 3200 rounds out of an advertised back tee rate seems a bit iffy, and it would be a 10-12% increase in play, which would be pretty good.
I have also heard the argument that the internet age, where your first new customer touch is likely your pictures and scorecard on your web site, back tee distance may even be more important. And, they may go to a tee time service, who may still harbor some length bias, which could hurt you.
I have seen some evidence that golfers check all the tee yardages when determining where to play. For instance, unlike my Dad's WWII generation, who would never drop below 6,000 yards, senior men today tend to shy away from a course without sub 6K tees.
If anyone thinks they have a good way to quantify the 7K barrier, like Ross Perot, I am all ears!
I am hoping when people see the ridiculously low cost/benefit ratio, it opens there eyes.