The anvil I purchased a few months ago is missing its heel, and the balance on it is fine (not tippy at all), so I suspect missing the horn would be fine as well. The one I bought is 180# with a pretty good face, and I paid $0.66/LB for it, or 125$. Anvils may be more expensive where you live however.
I know missing the horn and missing the heel are two pretty different things, but for what it's worth, my anvil has worked very well for me so far. I don't regret buying it for a minute.
If you can post a photo of the anvil in question, that may be helpful.