Sorry to disagree with you Dany but your idea of PSD – HTML and WP has different levels of authors is totally without merit.
PSD is the HARDEST category to get into (at least that is what we are told) – look at the influx of terribly designed WP themes on ThemeForest – over 50% look like free ones on the net – but SOME still sell in huge numbers.
For example one of DD’s HTML themes didn’t break 50 sales yet, after a considerable amount of time – but the WP version has some nice sales – which contradicts what he said.
I truly believe that everyone has to find their own business model when it comes to TF as an author. You MAY get wordpress only buyers who love your themes – but do not buy HTML as they do not want to convert – or do not know how – so they wait.
I have many buyers who ONLY buy my HTML Email templates – I create these as sister products to my HTML and Wordpress – but most have simply outsold the father product (HTML and Wordpress) by huge amounts – see what I mean – they are all different buyers – some buy only one type of product – others buy multiple.
Like I said – it’s up to you to work out the figures on what is worth you spending time on.
Dany was correct in saying spend time to build in features – when all said and done that is what Wordpress is for – and we must not forget that a large proportion of themes are bought by other developers, not for the design, but to find out how you did something cool, or implemented a certain thing etc