7.50/m will be good for unlimited data.
By DUN do you mean
1) Making a 9.6k GSM data call direct to your UK ISP
2) Making a 9.6k GSM data call to the ISP in the country you are in
3) Making a GPRS connection (to the local GPRS gateway as normal)
4) Making a GSM dialup call to an ISP but at some higher speed e.g. the Orange HSCSD 15-20k rate
?
I used 1) extensively in 2004 and it works very well. It even works reasonably well airborne (for very compact weather data websites only) while GPRS appears to be useless when airborne.
2) is just a case of opening a dialup account locally
3) should work anywhere
There are other GPRS options which are a lot cheaper than Voda. I think Tesco didn't charge at all for GPRS, for something like a year! Their billing system just wasn't in place. The reason a lot of people go to Voda (despite the highest prices in the business) is for relatively seamless operation abroad. And nobody else offers fax on PAYG. So I wonder how good T-Mobile will be on their European roaming arrangements...