Cheap, Great, Vacation Spots/Places, for Large Familys…?

Ok, so I (including counsins, aunts, uncles, and grandparents) live in a family of 18-20 people (depending on if my bro and sis will be back from the Navy and friend vacation). Anyway, this large family always go on a 5day-7day vacation somewhere. This year, Tennessee, last year, Schliterbahn, last last year, Colorado.
We want really cheap, but really fun! Not really like mountains and all, maybe beach, shopping, or just to chill. But I want your opinion on what would be good for us…
-we have no children under 13
-oldest is 80
-lots of teens
-more girls then guys, but about 9 of each
-we all get together well
-We all live really close to Dallas TX
-we are not “rich” and we would REALLY prefer cheap…(like $5,000 in all…also meaning that all 19 of us will spend about 5,000 in all)

Please help! we do not know what to do and I have been researching for weeks and can’t find anything!

P.S. the vacation will be the Summer of 2011!!! <3 Thanks!!!