Looks good, Ya gotta do what ya gotta do when working to a budget, as long as you stay safe.
The only thing will be placing the weight down on them accuratley on the negative part of the rep, technically you shouldn't be looking down whilst deadlifting. Once you start to get heavy, you will probably find the pitfalls with using them. But fine to start with.
You could, however, buy some plywood (heat bonded multi layer stuff) and cut circles out of the right diameter and use them as dummy weights to lift the bar higher. Most gyms will have some sort of plastic dummy weights to do the same thing when using light plates. This should work out quite cheap (cheaper than an olympic bar and iron anyway!) until you get your gear sorted. Nice find.
ED: TimD beat me by 3 mins!