I always find it difficult to suggest a full 4-season season setup that is also adequate for 3-season use.
My expertise lies with tarps and not tents; so if you are not interested then I apologize now for the post. My 3-season shelter as been the SpinnTwinn-- a great two person shelter and a palace for one in the 3-season Colorado Rockies. It weighs in at 9.8oz including line.
My winter tarp is an MLD Duo-mid, comes in at around 13oz.
Both cost less than your $300 price range and weigh under a pound.
I am not a hammock camper, but I do own a bivy-- a TiGoat which is 6.8oz.
So my three season shelter (Tarp, bivy, stakes) = 19.6oz. Total cost is about $300.
I really like the idea of just a lightweight tarp but im not a fan or crawlies or snakes. I kind of want somewhat of a shelter to kee[ stuff out. I really like the bivy idea for myself plus a tarp. the tent is going to be used for two people and we could split the gear between us.