Not particularly... an attacker with a rack of GPU filled machines will only find a valid block every 10 days or so, and blocks are valid for around 10 minutes on average: this is a relatively narrow window for double spending, and not an opportunity to waste on a small transaction.
There are other attacks that rely on the receiver being fenced off from the wider network, but those are even harder to coordinate.
There are other attacks that rely on the receiver being fenced off from the wider network, but those are even harder to coordinate.