Apparently the realistic costs are in the tens of thousands of dollars. And because there is no return on investment at this point, at least officially, for digital/HD transmissions, that extra money isn't being spent by most companies at this time.
I work in post-production at a facility that is HD-equipped. It is/was a chunk of change (we have HD capable effects, edit and finish stations, D5 decks, HD telecine, etc.)...but, alas, its the proverbial and literal "cost of doing business." Unless you're resigned to local access cable or doing industrial films...HD is the hallmark of professional level work nowadays. Even wedding videographers know that!
To look at HD broadcast as having 'no return on investment' is ridiculous. I can hear the same cheapskates using excuses like that when color came around. And HD, at this point, is just as 'inevitable'. These are the same network affiliates that spring for a new Doppler radar and make you suffer the endless promos pushing it as something that will transform your life if you watch their newscast. It simple: Buy it, provide the upgraded product...and SELL it to the viewing public!!!
In short, I agree, it won't have any positive return...if you don't bother to tell people you're offering it. Problem is, these are old school types, i.e. management who don't know anything about HD and the market for it (trust me, they are the majority--I've observed them wandering glassy-eyed on the NAB show floors for many years). To them, I have one thing to say, "Wake up, folks, it's no longer 1992!"
**BTW, the above comes from the frustration that the local Chicago broadcasts of the updated Star Treks are on a second-tier network that is 1) not in HD, and 2) while digital, their broadcast is in SD that is so damn compressed, my original SD Star Trek DVDs look like HD compared to the resulting smeary pixelated imagery they transmit. Embarassing. You can barely tell that these shows were revamped at all...nice. Its like washing your car, then looking at it through muddy goggles--Dumb.
Here's the article in the Chicago Sun-Times that heralded the remastered/enhanced show's debut:
http://www.suntimes.com/entertainment/television/53081,WKP-News-vidbits15x.article
They didn't bother mentioning that while it was HD mastered, it would actually be shown at 6pm Satudays in "Soft-o-vision". And I don't think I've seen ANY local advertising for the show anywhere. They probably have a $10/mo promo budget, which is too bad.