Alas, all of their SaaS plans have the same price: "negotiable". I never felt like negotiating, so I have no idea if they're affordable; unfortunately custom pricing usually means it's not the case.
Yes. This is what I absolutely hate - I will never 'ask for prices' because I know it involves a harass-y phone call in my future. Such a shame people aren't more open.
The robot I work with (http://wiki.ros.org/Robots/AMIGO) uses a proprietary stand-alone package from Philips which works really well.
Somehow, our license expired and now we use Festival, which works, but I really miss its old voice. Especially for Dutch text-to-speech it works quite well.
But for the life of me I can't find a link of where you could buy it.
Doing TTS correctly, with intonation etc. is really hard. Its not really my field, but I can imagine that getting intonation right is near impossible with just unannotated text.
I figured as much. I've been using Festival myself, which seems OK. But there appear to be a million voices and I have no idea which ones are supposed to be the best.
I know there are a million APIs for this, but most sound awful. I'd love a service that sounds as good as Siri.