Never mind the late penalties, that loan cost you an extra ~ 30% due to the increase in the value of bitcoin.
If you have the slightest inkling that you wont be able to pay back the short-term loan on time, DON'T borrow bitcoin. It's value can and does ramp up quite quickly. You'd be better off with the exorbitant rates on a credit card cash advance. It might be ~30% too but that's over the entire year; not one month.
could have ramp down quick too
you are expert hind-sight preacher
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
The fact of the matter is, I have stated previously that people should neither lend nor borrow bitcoin and also that I am fully against the usurious rates people charge for extremely short-term bitcoin loans. So in reality, I am not a hind-sight preacher.
You are a hind-end muncher
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)