You could of course use equipment from the 22 and keep the 22 simple.
I spent quite a bit on my 55 back when. Not sure what you could get away with now.
Think Christmas and someday.
Perhaps it might be best if you were to just use the 22 to learn by and gain experience, this will give you time to find another source for fish and alot of time to learn from this site. Take what you have in your tank and learn all you can about it, gain expereince so that you can post to others about it.
While all that is going on you can always check the newspaper for used tanks and equipment, you never know what might come up.
Put your summer to good use and look for odd jobs around the nieborhood that you can do for xtra money.
Just some ideas for you.