Think you also need to consider if your siblings are all on board with this plan. I get that you are anxious to help them - but just make sure they are committed to this process because if one or two of them are not, they have to let you know. I-130s alone will set you back $535 per person, and depending on timing, that fee increases over time. Not to mention costs that will be incurred for securing civil documents (in some cases, fixing them if there are errors), medical exams, more fees (AOS and IV fees for each person), photocopying or scanning (if they don't have their own peripherals), etc. (adding this) Needless to say, all of that adds up.
(I say all this because have a sister back home that I am concerned about - she lives with her common law partner and their son - and would like to discuss her options for either coming here or to Canada , where my brother is. For many years she has declined, and it is 12+ years later that she is now reconsidering her position.)