At $1800 for the fireplace in the link, dropped off at the street, that leaves you $450 to move it, set it, and I assume furnish and install a veneer. I think you're way light on your price.
I'm not sure what you're doing for a bar, but I have to imagine you're light there. Four barstools, figuring 2' per guest, is an 8' counter. If you're doing El Dorado's units and providing the countertop and veneer, I don't know if you're covering your costs.
When you say open shelter, are you talking a roof w/ no sides or a pergola? Last kit pergola I priced two years ago was a 15'x15' in untreated pine for $2800 plus freight, in cedar for $3800 plus freight. You still need to dig footers, supply concrete, and put it together.
No clue on the dirt work, but the concrete price would fly here.
I get that you're looking at this as an opportunity to learn as well as build your portfolio, and that's cool. You're still putting in the time, and leaving the customer with a finished product, and I assume you'll be standing behind your work. You still need to cover all your costs (which I'm a little worried you're not doing here) and you need to make something for your labor. If you're going to lose money on product and work for free, build a practice outdoor living space in your own backyard so you get to enjoy it, or do it for a charity and get the writeoff. Don't hurt yourself financially just to get something like this under your belt, because if you do this project at a loss you're still going to get called back for every issue, real or perceived.