We had a baby shower for our second baby - we let our three year old throw it and make decorations so she would be involved feel the new baby. I also wanted my second daughter to have pictures of a baby shower in her baby book just like her sister and too have some special items just for her. It was a smaller party, but I'm glad we had one for her as well. I've heard of a lot of people having a welcome party for second babies after they are born.
You definitely shouldn't plan your own baby shower for a second baby. If you are "low income" it makes no sense for you to throw a baby shower for yourself. Save that money and buy things for your new baby.