The LEGO® set 770, Rescue Set, was launched in 1975. It is made up of 132 pieces and comes with three mini- figures. These are the early attempts by LEGO® at smaller mini-figures. They did not have moving arms and legs and they had not started imprinting facial features.
I got the first set when it first came out in 1970’s and like every other child, opened the box and built it with a lots of joy. The first thing that struck me then, was how large the rescue helicopter seemed compared to other sets of its time. The large double moving doors on both sides made it fun to play with. There were other build options but I recall only building the hovercraft (see photos).
Later on, I bought the set new in box and since they do not come on market very much, the price fluctuates. I paid about $60 for the new set about 15 years ago. It currently has listed at about $175 to $250 for a set still in plastic and without any box damage. This is a cool 192% return on investment.