Near as I can tell from looking at the property is that it looks to be one and a half houses. That’s half of what it sounds like you have now. I’ll grant you the large lot, but unless somebody’s idea of the high life is living in a tent, I’m not sure how this place is going to work for what sounds like three families. That would be my biggest concern if I were you.
Granted you’ve seen it and I haven’t, so I may be missing something, but I’d also consider what_a_disasta’s comment on buying as a collective. And not to mention that $425K nets you $1,750 a month before taxes pretty easily.
And yeah, finally, take the advice of the others who’ve posted and don’t worry one bit about getting a sale for your agent. He works for you and the purchase has to make sense to you (and your group) both financially and with regard to quality of life. You’ll be living with your decision for a long time.