VENT about SIL/Breastmilk (long)

Ok, so a quick backround, my SIL had a baby in July 2010, she didnt want to breastfeed, but pumped. She has TONS of milk. Like 50oz/day. So, she pumped for like 5 months and then quit cuz she was sick of it.(which is around the same time I adopted my son) anyways, so she had 1000's /oz saved cuz her baby was never a big eater. So, fast forward- her baby is now 10 months old, and she still has tons of it left. More than she will eat before it goes bad probably. My other sister pumped for me after she weaned her daughter for about 2 months and i was soooo grateful to her for that breastmilk. She did it out of the goodness of her heart,(I did offer her some financial compensation, but she refused) Sorry im kinda jumping around, but im lossing my train of thought here. 2 months ago my SIL was going to buy a house. They arent in any financial sitation to buy a house and i gently said that i didnt think it was a great idea to do that considering that she was outta work for 6 months and has crazy CC debt. Anyways, i wasnt rude, i just had said, "X, this house needs alot of work, plus do you even have enough for the down payment AND closing costs??? Adding all that stuff up, it gets really expensive to buy a house." (and the problem was, we were texting, not actually talking) So, she texts me back and just said, Yes, we have all of that covered. So, no big deal, i text her back and say, "Well, good luck, i hope you get it." Fast forward, she hasnt talked to me in 6 weeks, has ignored every phone call, text from me except for like one. Has been so short with me in person. So, i finally ask her what the deal is, and she says she is just so offended that i would ask her about her financial situation and that i have no idea how much money they have (acutally i do because she told me their sitaution, but i dont really care one way or another) and that i was SOOOO totally outta line by asking if they had enough money to buy it. So, i didnt think it was a big deal at all but she clearly was really pissed about it for weeks, so i apologized anyways and i thought this was over and things would go back to normal. Well, she still hasnt really been talking to me the last 3 weeks and im just done with her. If she wants to let a very good friendship be ruined cuz i said one thing to offend her, then i dont know what to do about her. So, she texts me out of the blue tonight (first time in weeks) and says.... Breastmilk, $1/oz if you are interested. Let me know ASAP. I dont even know what to say..... You dont talk to me for weeks, are a complete rag to me, and now want me to buy your breastmilk for $1/oz which by the way, we dont have $600/month minimum to pay for breastmilk. ( I only produce like 4-5 oz/day) And given that their a bunch of morons with their money, i dont WANT to give them $600/mnth of my hard earned money for milk that probably isnt even good quality. She never ate decent while nursing, drank a few beers and wouldnt even pump and dump, so i dont know why, but this is really pissing me off that she would think that i should buy her milk. How about you just keep feeding it to your child instead of practically starving her because she doesnt want her to get too big. Am i wrong to be pissed off over this?? I didnt text her back yet, i dont know what to say. Kinda seems like im being petty, but i think given the events the past months, im not going to buy sub-standard breastmilk from her for $600+ a month. I think ill just take the high road and text her back and say, No thanks, Cant afford it. Bye. You think thats a decent answer??? Cuz if i would tell her how i really feel, it would contain some not so Christian like words, and i dont want to stoop to that. Thanks for letting me rant/vent. Rach