Meaning:
“可” means “possible,” “小” means “a little bit,” and “刀” here is used as a verb meaning “to knife.” This term, often used in online advertisements posted by individuals, means that “the current price is negotiable (can be cut slightly).” It frequently appears in the first line of an ad to lure potential clients.
Example:
A: 这个广告贴说一房一厅月租五千，可小刀，我还到多少合适呢？
Zhè ge guǎnggào tiē shuō yīfángyītīng yuèzū wǔqiān，kěxiǎodāo，wǒ huán dào duōshǎo héshì ne？
This advertisement says a one-bedroom apartment is for rent at 5,000 yuan a month, and the price is negotiable. What do you think is the appropriate price to ask for?
B: 还到四千五试试呗。快过年了，没那么多人租房吧。
Huándào sìqiānwǔ shìshi bei。Kuài guònián le，méi nàmeduō rén zūfáng ba。
Try 4,500 yuan. Chinese New Year is imminent, and I figure not many people want to rent an apartment now.