It really depends on what you want from the theme. If you want something really unique, with features not normally available in other themes, $xxx is the bare minimum you should be ready to pay.
It could cost you more than thousands of dollars if you want a desent great looking and functional theme, for a normal theme, it will only cost you $xx or $xxx. For personal usage, I would suggest you use a free theme, and change some code, it will cost you nothing.
The cost is highly depend on what type of design you looking for. But what i can tell you is the standard price for it is $100+ for a decent custom make template.
thnx for the input guys. I m looking for a magazine style theme but simple and elegant something like techcrunch,lifehacker n all.
It much depends upon nature of theme! regular & custom premium themes cost differently! but for any classic custom made theme around $100 is good price
While I understand your need for a custom theme, if you look around, you are bound to find loads of themes around which you can modify to suit you.
Depending on the quality of the finished product the most I would pay for a WordPress theme would be $100.
If your looking for a high quality theme expect to pay $200 to 300 or more depending on the features. If you pay less than $100, your mostly likely getting just a basic skin for wordpress. If your looking for a totally unique theme with a theme options page, features like jquery slider, etc, then it will definitely cost upwards of $300 from a good designer. Just a heads up!
Its hard to say... here I would guess you could get one for mid-high $xx but a high quality wp theme could easily reach $xxx or even $xxxx if professionally done.