I do the same as you did... pick some up here and there, for cheaper rather than more expensive. Got one like her with a jersey bull calf for $900 also, last fall.... just happened on her... put a 2nd calf on her, although she did not have alot of milk and I supplemented the 2nd calf with one bottle a day for about 4-5 weeks.... they both would go in the bunk and eat with her, and she had mothered both real well. She is now bred to our angus bull, and once she calves, I will try to put calves on her and then try to breed her back AI to a jersey... These 2 calves will be weaned off shortly, and will more than pay me back for her cost and the expenses.
I look for bargains, and we buy and sell some cattle... my son and I have a cow/calf operation and also buy some feeders to match some of what we have and make groups that are backgrounded to sell. I also have had nurse cows off and on for 40 years... I like my dairy cows...