Lobster is very expensive because Lobster is very difficult to obtain and farm and expensive to feed because they eat a lot.
Lobsters are also very prone to a contagious and deadly disease and the lobster eggs are also difficult to raise.
So lobster is very expensive because it cannot be mass farmed like other fish so if you want lobster you have to pay a premium to purchase and enjoy lobster.
Lobster while expensive is healthy for you in moderation and it's well worth the cost to purchase lobster because lobster is very delicious.
I have lobster at least 2 to 3 times per year when I can afford it and it's worth every penny.
If I could afford to eat lobster more often I would.