I purchased a Giant Boulder SE (I believe it's the 2008 model) about a year ago. I rode it on the road more than anything, and the main reason I had it was for bumming around town, or running small errands. However, recently I discovered a short (but fun) cross country course near my house, and I started riding it. The first time I just went through it slowly to see what it was like and make sure there wasn't anything I needed to be prepared for. It was relatively easy, mostly flat with small hills here and there. I rode the course one time and the chainring on my Boulder bent.
My dilemma is whether or not to upgrade the Boulder piece by piece, or build a new mountain bike. If I build a new bike, my budget is ~$1000. If I build a new bike it will probably be strictly for mountain biking, and the Boulder I will just fix as needed and ride it around town or whatever else. I have experience configuring road and track bikes, but I have never built a mountain bike before, so any advice would be appreciated. I'm looking for something that is durable, will allow me to ride easy to moderate trails, and isn't going to break apart piece by piece.
Any advice would be appreciated, TIA,