Panel 1: Ah, I hadn't thought of Weed as a potential business partner! Well, presumably he has a lot more saved up than Mike. (Incidentally, I wonder if the fact that his parents have $$ will come into it? He's determined to be independent, but he seems to be okay with having money, as long as it's all his.)
Panel 2: Weed, besides looking like Gloria Swanson in "Sunset Boulevard", also doesn't look too keen on the idea. It's usually foolhardy to say that an investment will pay for itself, and he probably knows that. And there's Carleen. Wonder if she'll contribute anything, or just continue to sit there, cringing. (But at least she has some wine, and it appears that one of the guys poured it.) ETA: Yeah, and why does Mike immediately (it would seem) go running over to Weed's to pitch his idea? Clearly Deanna knows how to crunch numbers, so why isn't he having this discussion with her? YetAnotherETA: And it seems that Mike has been possessed by Leo Sayer! "I feel like dancin'---WOO! Dancin'---WOO! Dance the night away!" That, plus his eyebrows make him look positively manic.
Panel 3: Well, I'm glad somebody brought that up!
Panel 4: What is a heritage house? Until I know, I can't comment on Weed's response. ETAAgain: Props to howtheduck for this: "The joke is a pun on the word “heritage.” Heritage is something that you inherit, so Weed is saying that if he buys the house, he will also inherit the repairs he mentioned as another heritage."