We anticipate about 50 people attending and spending about 15,000 for our wedding. I consider these expectations modest.

Your idea of "modest" is wildly skewed for someone with nearly no income and enormous debt and who is expecting someone else to foot the bill for this expensive party.

Your fiance grosses $75,000 and owes $30,000 on his student loans. You're expecting him to put aside $600 per month for 24 months to make your $15,000 wedding budget.

That's an insanely irresponsible way to handle his finances, and he is right to tell you this isn't possible. I think you should listen to him: You don't have money like that.

so we agreed to have a small wedding in 2 years and that he would pay for most if not all of it.

He wants a "small" wedding and you expect a "modest" wedding. You and he are 1,000 miles apart on the definition of "small" and "modest."

If you want a $15,000 wedding, you should probably wait until you can afford it. If your fiance had an extra $600 to put aside each month, he should be paying down that student debt as fast as he can.