Hi ericc,
if the physical aspects of this proposed purchase don't phase you, I honestly wouldn't let the idea of collimating put you off buying a 10" dob. Dobs are great scopes, and you'll get a lot of pleasure from using it.
Many people are a bit squeamish initially about collimation. But after a couple of goes you'll be wondering what all the mystery was about. You'll need some sort of collimation device - a cheshire ep or a laser collimator - but it really is easy to do. It takes a few seconds to check with a laser collimator, and then if some adjustment needs doing, that obviously takes a little longer. But we're only talking a minute of two here - not hours or anything like that.
If you think clearly about what it it that you're supposed to be doing as you collimate, it becomes easier to do.
With a laser coll for example, you're going to fire the beam down thru the ep hole, bounce of the secondary and onto the central spot on the primary. Adjustment of secondary may be needed here. Once done, you will be adjusting the primary, if necessary, to bounce the beam back up the same light path to the central spot on the secondary (not marked) and back through the ep hole (although the ep isn't actually there - the collimator is in it's place) and into the hole in the collimator that it originally came out of. Once this is done, the light path is good.
If collimation is out a bit, you'll still be able to use the scope without adjustments being made. You may perceive a slight degradation in the viewed image quality. If col is a lot out, obviously the viewed image is going to get worse.
Hope this helps, and good luck
