Davison Inventegraton a legit.company that provides positive results for product development or is it a scam?

I presented a product idea to Davison Invent. They want 685 for background research. In the future I will pay for product development maybe up to 5000 dollars. PT Barnum said there was a sucker born every minute. Does anyone have experiences with this form of product development with Davison Invent. as a middle man milking the inventor for money. Has your product ever made it to the store shelves?
Have you ever made enough in royalties to make up for the money paid to Davison Inventegration? Please information from outside sources would be greatly appreciated.

Scam. Don't do it.

See source link.

Have had some experience w/ Davison.
I paid the initial $600 or so fee for " market research "
Was somewhat disappointed in that they missed very similar products which I found by doing an independent "free" search at the US patent office site.
The "next step" was something of a shock .
It would cost $15,000 to have a model & custom packaging made for submission to the "targeted" manufacturer.
I felt this was just "eye candy " & any manufacturer would
be able to work from the detailed drawings I had provided.
While the work they do is well done & may have value to some ,It is very expensive.
They get a fee for these services which may or may not be completely necessary.
Unable to afford the final step, I dropped the project & ate the initial cost.
For any other product ideas I come up with , I will consult w/ a patent attorney & submit (since I can) any design drawings & patent applications.which are necessary
As far as a scam goes... as I said It is in my opinion eye candy & may be attractive to some who "agree" to pay a fee for the services they offer.
In their disclosure information DI does list a class action against them.
To be fair, I have seen in independent articles . mention of Davison for some of their own & submitted designs that have gone into production ( some "award winning" designs were among them).
They get a nice chunk for their services out front + an agreed upon percentage of profits, should there be any.
They will make money regardless of the success of the product ( which is basically how they make their profit) & any royalties they share in are just gravy.
Scam...don't think so......clever marketing ..yes, worthwhile expense...maybe?.
Buisiness ventures of any kind are a gamble & DI does not promise success.
There is enough of a percentage of people who have had success to establish legitimacy.
DI has no" skin " in the game & will profit one way or the other.
Interested party & will watch your posting to see if there are any responses to the return on investment part of the Q.
Best regards