No , no, it is 3k for transaction if she keep selling pupusas, remember we are using Maria's example here. With phoenix If I send you 10$ (~55k sats todays exchange rate) it will create a channel for you for ~52k with a little inbound capacity but not enough to receive another 10$. So if I send you 10$ 10 times, it will create 10 channels, charging you 3k sats each time (It charges the receiver). This is not good for Maria :(