Wow only $450 for the rent of a one bedroom. I've always lived in places where housing is really expensive. You can't get a 1 bedroom for 4x that cost in my area, nor where my daughter goes to school. I assume you are going by today's pricing and who knows what will happen with housing costs in the next 10-15 years.
Sorry about the allergies, that can be very scary. Good luck with that. I do know a kid that had a severe egg allergy that did get better as he got older, perhaps that will happen with your son.