I made some observations on the investment “value” for the starting wedding/portrait photographer. Researching the competition I saw 3 different wedding/portrait gear photo set ups in various websites, which seem representative of the investment ranges. The average investments seem to be between 1 and 2, in the $2000-$4000 range.
2 - had a pro DSLR, Pro lenses, pro portable studio (Investment $ 5000)
3 - had a digital MF, and pro gear (Investment $30000)
The thing is they all quote similar rate for a wedding, or a day of shooting. If this is the case there seem to be no correlation between the investment and the return.
The digital MF may look a lot more pro, but at the end of the day seem to be paid as little as the basic gear guy. So the ROI appears to be nil.
Durability? Well for fashion or studio photographers sure, they are trigger happy and can fill the shutter-count life expectancy of a pro camera in 6 months. Wedding photographers on the other hands have jobs in the dozens per year if they are very successful, so even taking pictures on the side, by the time they arrive at half-life expectancy their cameras are obsolete.
This guy I know started with his old camera and set up, and only added pro lenses when the money he made exceed their prices (essentially reinvesting a few month of work into gear)
But even in this case, while he has a more "pro" look that doesn’t seem to result in more customers or higher rates.
I observed that most customers judge on how things appear, a $30 eBay portable studio kit may look more “professional” than a weird looking “old-school” Phase one MF camera.
It seems the “smartest" wedding photographers are the ones with the absolute bare minimum to do the job, or a job anyways, with a $300-$400 entry-level body-lens kit.
What I couldn’t figure was customer repeat. Sure you can take great pics no matter what you gear is, but I though that possibly photographers with better gear would tend to be more dedicated and professional and hence generate more satisfaction for their customers, hence repeat business.
Is there any evidence that investing in professional gear is worth it?
TL/DR If you need the features of 'professional' gear it's worth the expenditure.
After wading through the question body I think that your actual question is: 'Why spend the money on 'professional' gear. If you're not going to charge extra for having professional gear'.
There's a saying along the lines of (if anyone can find the actual saying, please comment or edit).
'The gear you have is fine. Till it isn't.'
Lets explain this in more detail. You're shooting a wedding in a church with an entry level camera. You find that the inbuilt flash is awful. It's very strong and you can't direct it. Thus you buy an off camera flash. You can change the power and direction.
The next wedding you're in you're not allowed to use flash and it's dimly lit, so you have to crank the ISO up, but the noise is terrible. To avoid this in the future you buy a body with better low light capability. You choose to go full frame. But now your old lenses for you entry level camera don't work so you have to buy some new lenses.
The next wedding. Still allowed to use flash, but you're not allowed to get close to the bride and groom. You're at the back of the church. So you buy a zoom lens.
Next wedding you find you're outside and it's raining. You really need equipment with weather sealing. There's motion blur, you need more light so get lens with a wider aperture. Your camera breaks before the shoot. You need a second one whilst it's in repair etc etc etc.
In time you build up your gear as you need it. In the end I expect for wedding photography you will find you probably need 3 FF bodies (2 to use, 1 as a backup), mid range zoom, long range zoom, flashes and anything else you've accumulated such as primes, UWA.
Wedding photography however I would strongly advise not taking this approach if something goes wrong and you muck up a brides big day (and her mothers!) because you were inadequately prepared and all the photos are grainy/motion blurred. On your head be it.