Doors and Windows - Broken Seal on Slider

I recently bought an 18 year old townhouse that has a 6 ft. slider in the back with a broken seal on the left door. It looks AWFUL! I initially thought I could replace the whole slider for not much money, but I was surprised to learn just how much it would cost to do this-esp. since i need the exterior color to be brown to match with the development. So I was wondering if I could just have the broken seal replaced. Do they replace the windows as well or just clean them and put them back? As it is now, I can barely see out the window and there is dusty stuff that falls from top to bottom when I open it. Would I use a window place for this? How much should it cost? Also can I put new hardware on this old door to make it look a little nicer? The lock is broken too. And the final thing is there is a gap when I close the door-it shuts fine on top, but if you look at the bottom of the door, from the floor up to about 12 inches it isn't meeting-it's like the door is a little crooked in there-can this be fixed too?
Thanks for any advice.

Here's a post just a few weeks old, where the question about cost was discussed: http://forum.doityourself.com/showthread.php?t=288080

A glass company might also be able to get you some new hardware. The "tipped" door might be due to a roller that needs to be adjusted. Sliding doors usually slide on 2 sets of rollers, where each set has 2 wheels. Most often, the rollers can be adjusted with a screwdriver- they either have 2 screwheads or 2 removable caps along the bottom of the sash (the adjustment is done perpendicular to the rollers) or you need to open the door, and insert a screwdriver under the door from the side (the adjustment is done inline with the rollers). Sometimes the bearings will fail on the rollers and the door will sag and drag, or possibly the bearing will lock up and drag- even to the point of becoming flat on the bottom, in which case the rollers need to be replaced. At any rate, the company that replaces the glass should be able to do a "tune up" for you, for an added cost.

Since you mentioned that the gap is at the bottom on the latch side, that would indicate the the latch side rollers need to be adjusted UP, or the mullion side rollers need to be adjusted DOWN. After the rollers are adjusted, your latch will likely also need a slight adjustment to ensure it will lock.

Thank you!