Hi John,
I looked at getting print directly onto glass here in Aus as customers feel that print onto clear film is somewhat inferior. I approached 2 companies and both quoted me in the range of $500 per sq Metre - they also insisted on supplying the glass sheet themselves. This would put the price on a digital repro printed BG in the range of $300 - $350 each - hardly viable!
I also had the same reply as yourself - they would only do it as dot print which then gives the same result as a digital print to clear film. Difference here being though that i can afford to do double or triple print to clear film which gives a far greater depth to the finished product, not all washed out like alot of printed glasses.
Most printers are cutter also and if you know your machine owner well he would be more than willing to set up as cutter and printer and do a run for you... my guy will organise this if i do between 5 and 10 prints which is why i now do runs of 10 glasses at a time.. will send pics to your email if you like