I am just starting out with corals and you can expect to pay $15-100 for frags
up to larger corals. So far mine have ranged from $20-30 each. They are in my sig.
Mushrooms and many leathers are also rated fairly hardy. You really need to take a look at what you want and then develop a plan as like fish not all corals are conducive to being together.
Keep in mind that even though it may seem like you have a lot of lighting with your 260w pc
you are really at the low end of the light requirements. If you cannot upgrade right away look at corals that require low to moderate light and then place them in the top 1/2 to 1/4 of the tank.
Here is a good resource for reviewing coral requirements:
One thing that has not been mentioned is water source. What is yours? RO
is rcommended. If using TAP you need to be careful.
With corals there is more to test for than amonia, nitrites and nitrates. Recomend you get a CA
test kit and check that. Also take a look at phospahates especially if you are using TAP water.
You can definatley look at getting some easy corals, but personally I would wait until your system is a bit more mature and you know all the water specs are in line. Also, you need to have a plan for fish. As mentioned before IMO
the lion and eel are not a good idea.