When I redesigned my sites, I opted to go for a DIY approach with GeneratePress over getting a designer to work on a fully customized theme.
Part of this was the economics of it all- a fully customized site costs over $5,000 (and I have two sites with a third coming soon) and a DIY theme costs roughly $50 per year plus my own time in customizing. But the other part was that I am not convinced that aesthetics actually matter when it comes to the performance of your site- not for an extra $4,950 per site at least.
Sure, there are some things that are necessary in order to convey your expertise on a topic and to help with the user experience. But at the end of the day you can convey your expertise with text and social proof, and the most important aspects of user experience are based on site function, not site form.
Design aesthetics, which is what a customized theme really is, only minimally come in to play with any of these.
So if you are thinking of investing thousands of dollars to redesign your site under the thought that all the bells and whistles will get you more page views, you may need to think again. If it were up to us, we'd spend that money on a different outlet altogether: marketing.