If I purchase Unity Pro 4, do I get access to Unity Pro 3.5.X?

I’m currently working on a project with a few other devs that use Unity Pro 3.5.X, and it would make it much easier/‘safer’ to also be working in Unity Pro 3.5 (I do my work in Unity free right now, and submit my work piece-meal to them for testing/integration into the project). I would really like to buy Unity Pro 4.0 for other current/future projects, but would like to know if by doing so, if I would also be able to download Unity 3.5.X to use for this project as it nears completion. I would really not want to be forced to buy Unity Pro 3.5.X now, and then also buy Unity Pro 4.0.

Thanks in advance.

You should contact Unity directly about that. I’ve found Unity’s support to be helpful and willing to work with people. For anything that isn’t explicitly stated on Unity’s website you really need to ask Unity for details.