Former Blackburn Rovers defender Samba returned to English football in January when Harry Redknapp identified him as the man to lead QPR's survival bid.
The centre-half did not come cheap, though, with a £12million transfer fee and a sizeable salary shelled out by Rs owner Tony Fernandes.
Samba has been accused of moving for financial reasons, rather than footballing ones, but he is determined to prove his worth and repay the faith shown in him by helping to preserve QPR's Premier League status.
He told The Sun: "I don't know how you judge if it's too much money, but I know some people do.
"Is £12m too much? I don't know. Or if it was another player would it be okay? Maybe someone else is more worth it? Maybe some people believe what I have done in football, my reputation, what I did at Blackburn was enough for this.
"I'm not there to judge it. I've been bought. It's not me who chose to buy me. I didn't set the price. I've been bought for a reason, because QPR believe I can make a difference.
"I certainly believed I could lead the team. I don't know if it will be enough but, one thing is for sure, I will do my best to help the team."
Samba, who was snapped up from wealthy Russian outfit Anzhi Makhachkala, added: "Tony Fernandes showed great belief in me and I will try to pay him back.
"I think the transfer came across totally wrong because of the valuation. At Anzhi, I had three years left on a big salary so, obviously, if I came to QPR it was not to make more money.
"I came back to England for personal reasons, but I'm sure that Anzhi will be one of the biggest clubs in the world."