Actually, I cross both scenarios.If you use your projector only for fun and hobby stick with a project build by yourself or someone here on PL. If you use your projector professionally then having a company behind you that takes care of all your modules is a must. I give 1 year warrenty and 2 years of service etc but yes the price is different but you get more for this then only a module
I use my projectors for business, but I am capable of my own maintenance. What I don't have the ability to do is make core compoenents such as nice flat baseplates and optics mounts. My favourite module to date was the kit that Dave did for the dual knife edged 445, as it took care of the all the components, but I could assemble as required, and it's something I can service myself. Hence the requirements to keep it as simple as possible. Realignment and diode changes and driver adjestments should be easily within the possibilities.
To be honest, if something has to get shipped anywhere for a service or warranty repair then I've kinda failed.
This part in particular, I really can't agree with, unless of course that company is mine
If you use your projector professionally then having a company behind you that takes care of all your modules is a must.