Dale Stephens' overhead kick and Rajiv van La Parra's long-range strike put Albion 2-0 up early in the second half.
But Austin, back in the starting line-up following a calf problem, pulled a goal back and the visitors were reduced to 10 men on 84 minutes when Lewis Dunk was shown a second yellow card following a challenge on Sandro, before Alejandro Faurlin's corner three minutes later was headed in for the equaliser.
It took Austin's tally for the season to 10 and is bound to increase speculation that Rangers might sell during the January transfer window rather than risk losing him on a free transfer next summer, when his contract is due to expire.
"In football there are no guarantees and everybody wants to make a profit," Hasselbaink said.
"At the end of the day it's a business
But do we want to sell him? No.
"It's up to the owners and as a manager I can only advise and can only say 'No, I don't want him to leave - I need him' and I think they would respect that.
"I'm, very happy with his goals but he's done so much more than that with his work off the ball.
"But it's not just about him
It's about the team and he doesn't score if the ball doesn't come in and if other players are not prepared to sweat."
Hasselbaink felt his side created enough chances to have won the game and that Van La Parra fouled Sandro in the build-up to the Seagulls' second goal.
The Dutchman said: "I think it was a foul
It's a push in the back and when you get a push you can't jump.
"The referee should have seen that and he didn't, and for the second goal we were still thinking about that.
"But we showed enormous character to come back and I think we deserved all three points.
"There was only one team in it in the first half and apart from 10 or 15 minutes in the second half I'm very happy with the performance."
Brighton boss Chris Hughton, whose team are unbeaten in the Sky Bet Championship this term, remained upbeat despite Albion being replaced at the top of the table by Middlesbrough.
Hughton said: "At 2-0 we knew they would put pressure on us and it would probably be hard not to concede with the quality QPR have got and the pace and power they have.
"Their first goal changes things because it gives them the lift they need and the second one comes when they have a lot of bodies in the box - they are a very powerful team.
"In the end we also had to be strong during a period after their second goal and make sure they then didn't score again
That's the plus, because we could have lost this game.
"When you're looking for perfection, you always analyse things like how you conceded goals, and I have a very disappointed dressing room in there.
"But there are certainly more things to be happy about than unhappy
It's a very tough division and it's always very tough to get results away from home."
Source : PA
Source: PA