How much should I charge for a wordpress template?

Carlos Diaz this is what I do with one of my personal business: http://wideskydesigns.com/

I would first decide what you feel your time is worth. Just because somebody will do it cheaper shouldn't drive your price. Factors in deciding that would be the effort you put into learning the new skill. Think in terms of Amazon. You can build an online store just like them. However you cannot compete with their prices. You can compete on customer service and knowledge.

So if someone says they can get it cheaper somewhere else that's fine. But they can't get you somewhere else. It comes down to what you feel your time is worth. I'm sure you already have that number in your head. Any number below that is what creates the uneasy feeling.

Why not just charge an hourly rate for this particular job?

If you are not used to working on different types of projects, or working / being paid for development work, then start at $xx price, and then go from there.

Carlos that is for you to decide - I live in a different country, region, have different skills, overheads etc - so me telling you what to charge means nothing.

You have to just decide a figure, then go from there; if you find it isn't enough, you know to charge a little more next time - if it's too much the client will probably leave or will try to negotiate.

It's always a fine line but the range of prices people charge is $10 to $1000 - so no-one can tell you a price. You have to make that decision.

You're in tricky waters. By not knowing how long it's going to take, do you 100% know how you're going to do it? I ask because I know how long something is going to take me to do so I can then work out a price, much like you do with your 5 page static sites.

Perhaps, you should let this one go by the wayside, or offer him an introductory rate just so you get some experience. Modifying themes requires a very good understanding of how WordPress works to do it quickly and effectively.

You'll HAVE to look at the theme before estimating any time quantities. Some themes look great but are the worst thing on the planet to work with as they've been written by complete morons.

Experience is what you need here, do this one for free or cheap...attribute it to learning so that next time you can say exactly what you need.