There surely seems to be a difference (read: clash) of values between you and your parents on this subject.  For you, you wish either to restrain what could be perceived as conspicuous consumption or to use your (your family’s?) financial resources in other ways. 

For your parents, they are elated at your upcoming marriage.  They either want to have a blowout celebration or, as you describe them as “very upper middle class and slaves to society”, they may have a range of social obligations to repay.  You may also have a very large family that needs hosting if you all anticipate or desire a weekend of events.  A large party can fulfill these or other needs, of which you may or may not be aware. 

From a Jewish standpoint, we sure would not want resources to be used inappropriately, and much of Jewish law frowns upon ostentation.  Jewish law and custom surely approves of the acquisition of wealth, but those who attain it should use it to help others (tzedakah, that is), and not use it for personal advancement or aggrandizement.  Deuteronomy (15:10) reminds us that we should “give generously to them [the needy] and do so without a grudging heart; then because of this the Eternal your God will bless you in all your work and in everything you put your hand to”.  Other similar references can be found in Isaiah 1:17-19 and Proverbs 19:17.

When it comes to displays of wealth, the Talmud takes a view that unnecessary ostentation leads to envy and, perhaps, to anti-Semitism.  When in Genesis 42:1, Jacob wonders about why his sons just sort of stand around looking at one another and doing nothing during the famine, the Rabbis of the Talmud give a slightly different spin to Jacob’s observation.  In Babylonian Talmud Ta’anit 10b, this was Jacob’s speech to his sons:  “Do not show yourselves to be sated either before Esau or Ishmael in order that you do not arouse their envy against you”.  Some read these words as warnings about the Israelites displaying their wealth to the nations around them.

Another reason to restrict the display of one’s wealth, as we read in tradition, is to protect the poor, who would not otherwise have the means, of trying to “keep up” with others in society.  Some may consider borrowing far beyond their means, and others might even engage in illegal or unethical behavior to achieve what they see in others.

In an article, “The Simple Life: The Case Against Ostentation in Jewish Law”, Hershey H. Friedman, Professor of Business and Marketing at Brooklyn College of the City University of New York, brings forward this interesting passage from Babylonian Talmud Mo’ed Katan (27a-27b) regarding the changes that were enacted in the funeral ceremony in order not to humiliate the poor [http://www.jlaw.com/Articles/againstosten.html]:

“Formerly, they would bring food to the house of mourners in following manner: to the rich, in baskets of gold and silver, and to the poor in wicker baskets made of peeled willows.  And the poor people were ashamed.  The sages therefore instituted that all should be provided with food in wicker baskets made of peeled willows out of deference of the poor. 

Formerly, they would provide drinks to the house of mourners in the following manner: to the rich, in white glass [which was very expensive], and to the poor in colored glass.  And the poor people were ashamed.  The sages therefore instituted that all should be provided with drinks in colored glass out of deference to the poor.

Formerly, they would uncover the face of the rich [corpse], and cover the face of the poor because their face became blackened by famine.  And the poor people were ashamed.  The sages therefore instituted that all faces should be covered out of deference to the poor.

Formerly, they would carry out the rich [corpse] in a state bed and the poor on a common bier.  And the poor people were ashamed.  The sages therefore instituted that all should be carried out on a common bier out of deference to the poor…”

Finally a conspicuous display of wealth can lead to conceit and haughtiness, characteristics that the Rabbis wanted us to avoid.  The most common passage in Torah on this subject is this one from Deuteronomy 8:10-18:

“When you have eaten and are satisfied, praise the Eternal your God for the good land God has given you.  Be careful that you do not forget the Eternal your God, failing to observe God’s commands, laws, and decrees that I give you this day.  Otherwise, when you eat and are satisfied, when you build fine houses and settle down; when your herds and flocks grow large and your silver and gold increase and all you have is multiplied, your heart will become haughty and you will forget the Eternal your God who brought you out of Egypt, out of the land of slavery.  It was God who led you through the vast and dreadful wilderness, that thirsty and waterless land, with its venomous snakes and scorpions.  It was God who brought you water out of hard rock.  It was God who gave you manna to eat in the wilderness, something your ancestors had never known, to humble and test you so that in the end it might go well with you.  Beware that you don’t say to yourself, ‘My power and the strength of my hands have produced this wealth for me’.  But remember the Eternal your God, for it is God who gives you the ability to produce wealth, and so confirms God’s covenant, which God swore to your ancestors, as it is today.”

In the final analysis, your parents may do what they want; it sounds as though they are paying for the wedding in any case.  But perhaps you can ask them to tone down the party to reflect their need for social obligations and your desire to make this an appropriate party.  Bear in mind that, in the realm of Jewish celebrations, a wedding is the happiest of occasions that we celebrate, and some people feel they want to go all out for it.

So what can affect the costs?  An afternoon affair is usually less expensive than an evening party.  Certain outdoor venues can be inexpensive or costly; it depends upon demand.  Certain menu selections can be less costly.  So be creative, and also be willing to compromise with your parents on some of these matters.  Your values about avoiding ostentation – for whatever reason – are just as valid as theirs, and you probably should try to meet halfway.