Unless, of course, my client wants a 100% working no-script webapp/site. Then I'll happily charge for the extra time building it.
If it takes more time, the final product costs more. The client should be aware of that and make the decision. Why should he/she always pay for something that will only be useful for a very small % of his/hers clients?
Regardless, there is no right or wrong answer in general, there is only the right or wrong answer for your particular website/market. If a significant number of the users you want to support have JS disabled, then by all means, build a site that runs without JS. But it's a cost-benefit analysis. For most sites I've worked on, the cost of lost business due to users without JS is (massively) dwarfed by the added development cost of building a full-featured app that doesn't require JS. If that means I lose you as a customer, I'm not losing sleep over it.
If just I look at my logs, more than 90% of the access are from Firefox and don't run Javascript.
Similarly, I won't be testing my websites in Soguo or Yandex until more than a vanishingly low percentage of people are using them on those sites.
If I have a blog or similar media site, and require javascript, I might offer a 15/month option to allow access to a text only interface and an RSS feed. No graphics, no pictures, a very simple link and text interface.
And the moment I start seeing subscriptions coming in, I'll believe in progressive enhancement again.
(Progressive enhancement doesn't affect me as an application developer in the web space. But if it did...)
If it were a site I frequent, I'd probably be willing to pay $3-4/month for a simple, clean, static html version (no need to remove the pictures though -- I can choose whether to load those client-side). Something like this, say: [http://mnmlist.com/unknown/] I'd only pay 15-20/month if I could get the entire web like that :)
Most likely, at 15/month I'd just not visit your site.
EDIT: PLEASE don't use the navigation from that site though. It's ... way too vertical.