DaVince said: "Also what is the point of the last panel?"
He says ¥1000 is too much and then pays ¥1000 anyway after the seller lowered the price.
The caption says "Don't Split Up A Happy Family".
It implies all 4 of the yukkuris belong to a single family unit. The seller lowers the price to 2 for ¥400 from the original ¥1000 for 2, after haggling. So the buyer is happy to pay for all of them for ¥1000, even though he could've gotten ¥200 change.