Try central coast campers, they are a copy of the complete campsite as the bloke used to work for them and they are in your price bracket.
No affiliation just have a couple of mates that went down the same road, 1 of them flew up to the Brisbane show settled on a complete campsite which are made on the central coast then I told him about central coast campers which he drives past several times a day he ordered one the following week and saved $15-$20 thousand