Outstanding special effects with what is considered, in American terms, as a very limited budget. Business as usual for Doctor Who.
Doctor Who isn't that far off from an American budget. It's not like the '60s, where
Evil of the Daleks was three times the length of "City on the Edge of Forever" and done on half the budget.
The first season cost more to make than later seasons because of Eccleston's salary and the need to build standing sets, and it came it between fifteen and twenty million dollars. Later seasons cost less; no need for standing sets, and Tennant made less than Eccleston. (He also made less than Billie Piper in the second season.) The budget for the second season was a bit diminished; besides Tennant's lower salary and the already built sets, the expected money from the American sale didn't materialize. (The BBC wanted fifteen million dollars for
Doctor Who, but no American network was going to pony up that kind of money for a show they had no control over and no ownership stake in.) The fourth season was probably back up to the fifteen to twenty million range, due to Tennant and Tate's salaries.
I've not heard anything on the budget for the specials, but I imagine they've been done on a budget of roughly a million and a half to two million dollars.
By way of comparison, the McGann movie was done for something between four and six million dollars. In 1996 dollars. They sank a
lot of money into that TARDIS set.
ETA: Here's some more analysis of Doctor Who's budget. Basically, the show is budgetarily on par with what the studios spent on
Battlestar Galactica or
Star Trek: Enterprise.
ETA2: And Matt Smith is a veritable bargain compared to what lead actors in American dramas might pull down.
A million pounds over five years, while Tennant, at the end of his tenure, was a million pounds a year. At least the BBC has Smith locked down under contract for five years. Shows in the UK don't often contract for multiple seasons.
