Sorry to hear about your mishap.
Not knowing how huge the huge rip is, it may be able to repaired and still be a sound permanent repair. If you have some pics to show, or email, can look at it and make a judgement call.
To your first question, this post may help with cost but this included some new wood and only I think it was 8 to 10 feet worth.
The biggest cost difference is finding a place to do it. The labor rates will be different and this is the biggest cost difference. A good independent guy verses a large dealership may be a lower cost option.
Someone else just had a new roof put on approx. a year or so ago. I can't seem to locate that post right now.
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
Google Custom Search For Sunline Owners Club