if you are lifting 200kg on anything other than deadlifts you'll also need to consider a rack or cage to be safe.
I'd be inclined to just buy a normal 150KG bar and when you get to lifting more than that it is time to think about upgrading kit or joining a gym.
When you add the cost of a decent rack/cage and olympic bar and weights for over 200Kg + a bench to handle it you are talking at least £500 which is a lot of gym sessions.
I face a similar problem with currently squatting 180Kg for 8-10 reps and decided to do the lighter stuff i.e. shoulders and arms at home and the heavier stuff at the gym which I do once a week for £5. Thats a lot of gym sessions plus I can use other stuff such as chin bars, rowing, dipping etc. Without the space it takes up.
All just IMHO of course.