Check your nearest hire shop. The cost of buying one will pay for a lot of hiring.
If you buy one, it will stand in the corner of your garage/shed/workshop and be used about 5 times a year.
I wouldn't get anything less than a 6 tonne machine. I hired a 4 tonne one a few weeks ago and it only coped with the smaller straight grained logs.
The only downside of these machines is that they are designed to keep your hands pressing buttons to operate them so that you don't lose any vital parts while it is working. This slows down the splitting process because you are waiting all the time when you could be stacking the split logs and getting un-split ones ready to split.
Also, they are very heavy so transporting is difficult unless you are a weightlifter in your spare time (if you have any!)
NN