Dangerous.
Whenever money is involved there is a grave danger of outright dishonesty or at least misleading messages, cutting corners, cheating etc. etc. Taavas mamon is an illness which afflicts almost everybody. Chazal already said רובן בגזל - almost EVERYBODY is guilty of stealing on some level. Borrowing without permission is a form a stealing [שואל שלא מדעת גזלן], borrowing something and forgetting to return it is also a form of stealing. Cheating on taxes is another common one. Some people don't just engage in subtle forms of thievery but are straight out thieves. All of this is because of people's life long love affair with money. This feeling of love and connection also prevents people from SHARING their money with those less fortunate.
It's MY money. Why should I give it to someone else just like that??!! [Answer - Because G-d said...:-)].
When religious matters become intertwined with financial matters there is a great reason to believe that things are going to be shady. There are countless examples of this. Here are a few:
1] Pesach Hotels: Can you really kasher the whole hotel in a matter of hours? Can the mashgiach really make sure all that everything is being done according to halacha? How about when someone needs a fork and there are no pesach forks. What is going to stop the Hispanic waiter from bringing a regular fork? I once spoke to someone who worked in a Pesach hotel and he was of the opinion that it is impossible to ensure that everything is done according to halacha as it would be in one's home [he actually witnessed a waiter taking a treif piece of silverware and giving it to a guest]. But there is huuuuuuge money involved so who is asking...
2] Or the Kosher Switch as a f'rinstance. On their website, they feature videos and articles and vidoes by rabbis affirming that it is a wonderful kosher product with no problems of chilul shabbos.
Beautiful.
Why don't they also feature videos and articles by rabbis asserting that using the Kosher Switch constitutes chillul shabbos mi-dioraisa?? Wouldn't that be the most intellectually honest way of acting. A person should know that what he is doing has the stamp of approval of "rabbi x" but according to "rabbi y" he is a mechalel shabbos and wine he touches is treif etc. etc. and attains the "privileged status" of a gentile with regard to certain matters.
I am not deciding the matter of whether or not it is permitted - just pleading for forthrightness and honesty. But there is big money involved here and THAT is the problem.
3] Hechsherim - I need not elaborate on how many tzaros we have had from illegitimate hechsherim. But kashrus is a big money business and therein lies the problem.
The list is long but the principal is one: When money is involved be wary.
The limmud for us before the great holiday of zman matan torasainu is to try to uproot the cancer of ahavas mammon. To instill within ourselves טוב לי תורת פיך מאלפי זהב וכסף and וכל חפציך לא ישוו בה - All of the money in the world does not equal Torah.
אשרי הזוכה!!