I've breastfed 3 babies now, and pumped milk for all three as well. I found pumping pretty challenging - so don't give up if you have to play with it a little to get it to work for you! :) Talk to your lactation specialist at the hospital about pumping.
I have owned the Medela Pump in Style (over $300) and I've also owned Dr.Browns manual pump, as well as been given the free Medela manual pump at the hospital.
I had problems with the Medela PIS because I am a very large cup size and the mouth of the pump didn't really massage right. The best way I got milk was to express on one side, while the baby nursed on the other. (It helped my milk come down)
I was very happy with the Dr.Brown manual pump. It was about $50, easy to use, and doesn't have a cone shape, so it fits all sizes of breasts.
I also have a friend that loves the Advent manual pump, she's a normal breast size (c cup) and found it better for her then the rental she had from the hospital. It's about $50 as well.
As to the hospital rentals like the Lactina - it takes the manual medela pump and just pumps it for you. Uses the same parts.
As a side comment - never buy a used breast pump. It's not sanitary and can pass disease to your child. (unless they are medical grade -- like the lactina -- you can buy packages of the parts that need to be replaced)(Pump, tubing, cups)
Good luck and congrats!