Rovers looked the stronger side for the majority of the South Yorkshire derby, but they failed to convert their chances and paid a hefty price when Adam Hammill snatched a classy winner for the Tykes in the 74th minute.
The result was Barnsley's third straight win, but O'Driscoll, whose side have now failed to win in seven games, was in little doubt that Doncaster should have taken the points.
"Getting beaten when you have outplayed the opposition is something of a common theme for us," he said.
"We've been here before.
"But I would take that performance every day. If we perform like that every week I will have no complaints, but I am disappointed with the result. If you don't take your chances you give the opposition a chance.
"We don't score goals. Any man in the street can tell you that. To score you need to create chances and we do. We have most the attributes, we are just missing that little bit at the end."
O'Driscoll confirmed he has considered signing extra striking options, with Wolves' Sam Vokes on his list, but admitted cost was proving a stumbling block.
"Again it comes down to money," he said. "We can't compete with some clubs in that regard."
Despite his side's attacking problems - they have scored just 11 times in 12 league games - it was O'Driscoll's defence that looked a little shaky early on.
Hammill's weak shot had Rovers goalkeeper Neil Sullivan scrambling across his line inside two minutes and moments later Iain Hume had a clear sight of goal but dithered in possession and allowed Sam Hird to intercept.
Emil Hallfredsson then threatened with a header in the sixth minute before Doncaster charged back.
James Hayter poked wide from five yards after James Chamber pulled the ball back from the byline and in the ninth minute Billy Sharp had the ball in the net only for the effort to be disallowed for offside.
Rovers' James Coppinger then went close when his flicked header from a Gareth Roberts cross forced Luke Steele into making an acrobatic save.
After the break Doncaster maintained their fast pace and Dean Shiels curled a shot against the bar before Martin Woods then drove a free-kick marginally wide.
But for all their possession Doncaster were soon chasing the game.
Hume's corner found Hammill at the near post and the winger was given space to turn and blast a shot across Sullivan into the far corner.
"We made one mistake and that's enough at this level," O'Driscoll concluded.
Barnsley boss Mark Robins, meanwhile, was impressed by his team's discipline.
"We were under the cosh for a lot of the game, but we kept our shape and that's important," Robins said. "It was very similar to the Swansea game; you have to keep your discipline and that is what we have done and we got a good goal on the back of it.
"Once we got the goal we improved a lot. I think there was a bit of anxiety in our play and that was apparent until we scored and then we got a lift and some confidence."
He added: "From my perspective that's a magnificent three points. It gets us nearer the middle of the pack. This is a tight league and a win like that has a big effect. I am extremely happy but we have another tough game coming up against Nottingham Forrest."
Robins was full of praise for his match-winner, who has now scored three times this season.
"Adam is a good player and a real talent," he said. "He still has to learn the defensive side, but he is improving all the time and he is popping up with goals as well. He will take confidence from that and grow. He is only a young kid."