2. A store purchased a certain number of student-specific scientific calculators at the beginning of the school year for 880 yuan, and sold them at 50 yuan each, which were quickly sold out. It was found that students still needed 3 times as many calculators, so the store purchased the required calculators for 2580 yuan, with each unit price being 1 yuan cheaper due to the larger quantity. The store still sold them at 50 yuan each, and finally sold the remaining 4 at a 10% discount. The total profit from this business is ( ) yuan.
(A) 508
(B) 520
(C) 528
(D) 560
2.B.

Let the first purchase of calculators be $x$ units, then the second purchase of calculators is $3x$ units. According to the problem, we have
$$
\frac{880}{x}=\frac{2580}{3 x}+1 \text {. }
$$
Solving for $x$ gives $x=20$. Therefore, the total profit is
$$
(50 \times 76+4 \times 50 \times 0.9)-(880+2580)=520 \text { (yuan). }
$$