Why do you say that? It can be done more reasonably if you are willing to only pay Disney for park tickets and, if you have a car, the parking. Everything else can be done on a budget. Stay offsite, an AirBnB or off site hotel, bring your own food and beverages in, think about how much you'd eat on a normal day and pack that amount plus a few extra snacks, a refillable water bottle or bottles of water from Publix or WalMart, I never buy water at Disney, find out where all the refillable water stations are. I know of one at the DHS bus stop by the bathrooms and the one at GE, I don't know if there are more, maybe others know their location.
I don't know how old your little one is, but, for his birthday and even Christmas ask for money as part as his present that can be put away for his spending money and Walmart and Target have a great range of Disney souvenirs.
I didn't go to Disney until I was probably a lot older than you are, it's never too late, just look to ways of saving money, even if it takes a few years it's better than never.