My question is essentially identical to the one in the Reddit post "Simony and wedding fees", which has yielded no satisfactory answer.
Essentially, how are wedding fees charged by a church not an example of simony? I am of course excluding fees for unnecessary parts of the sacrament like a choir, photographers, etc.
It seems that in researching this question, the most common answer I come across is along the lines of "the fee isn't for the sacrament itself, but rather for the space, time, etc." However, these fees are still inexorably linked to the sacrament, and ultimately must be paid to receive the sacrament. If a church were to offer a standard free Sacrament of Reconciliation, but confessors were required to pay a "confessional upkeep fee" in order to have their confession heard, I think people would consider this a clear case of simony.
Another answer I hear goes "If a couple were truly unable to pay the fee, they could talk to the priest and have it waived. So the fee is really like an optional donation, similar to the collection basket being passed around at mass." Again, however, I believe that this is a different scenario. There is no concept of needing to donate to the collection at mass to receive communion. A person not able to make a contribution to the collection does not have to take their case up with the priest to receive communion. The act of receiving communion, and the act of making a contribution to the collection, are completely distinct events.
The OP of the Reddit link has expressed these and other arguments much more fleshed out, so I recommend his question for reference.
An example of the fees I am referring to can be found on page 11 of the St. Patrick Cathedral General Wedding Instructions/Guidelines in NY.
Roman Catholic answers please.