The majority is turned into hash, yes.
If you include equipment costs then definitely not, but realistically you should get a lot more profit.
Doing some basic math (lots of assumptions here).
If you have 16oz of fresh buds and you get 20% return on hash, then 80% return on rosin you're looking at 72g of hash rosin. Let's say oz's of flower go for $200 each. Hash rosin goes for $100 per gram (or more), so you're talking $3200 vs $7200. That's without factoring in labor savings from trimming or labor for washing, but it gives you an idea on how to calculate based on your local market.
Keep in mind that flower can be bought just about anywhere, but high quality hash rosin pulls a premium due to quality and rarity. (Most people only get it from dispensaries.) Dispensary pricing is crazy so it's hard to judge local markets -- you can see oz's of flower upwards of $500 and BHO going for $90 / gram here in Michigan. Crazytown...