I bought the laptop ( ) $500 括号里填什么?by for?或其它的词?

I bought the laptop ( ) $500 括号里填什么?by for?或其它的词?
I bought the laptop ( ) $500 括号里填什么?by for?或其它的词?

I bought the laptop ( ) $500 括号里填什么?by for?或其它的词?
我觉得这两个介词都不对
paid ..钱 for sth.
buy sth. for sb. 买什么东西给某人
我觉得应该填写at
at xx 以...的价格

for
buy sth for some money
以……的价格买下某物

for

for

填for.
例句：
He bought the canvas for ten thousand dollars.
他以一万美元买下这幅油画