You're right, it all depends on where you from. For me, that's about all I could charge for something like that where I live. Your best bet as far as pricing is to try to research other cake makers in your area and see what they are charging. If the one pic you have posted is the kind of work that you do, then you definitely have skills so don't undersell yourself.
I live in a very remote area and have never had a problem with pricing my wedding cakes and rarely does anyone balk at them. However, when it comes to occasional cakes, people just don't get it. I've been doing this for five years and have struggled with pricing my occasional cakes since the start and I'm sure I've underpriced most all of them! Last year after completing another back-breaking cake (the basket of crabs in my pics) that took me MANY, MANY hours (sold it for $200 and that was high for me), I finally decided enough was enough and have tried to stick to my same per-serving base price as my wedding cakes. Needless to say, it has significantly affected the number of orders I get for occasional cakes. Which is fine with me (thankfully, this is just a hobby so I don't count on this a "real" source of income) because then the people that do order from me are the ones that "get it" about custom cakes.
So I guess what I'm trying to say is you need to decide what's right for your area and also what kind of clientele you want. If you're too cheap you'll get everyone that wants something for nothing, if you're too expensive, you'll get limited orders.
I look at it this way, I'd rather sell one cake for $300 and make $100 profit, than 10 cakes for $50 to make the same amount.