I know that many others will chime in on this, but everything I have ever heard about a boat with soft hulls is to walk away. Keep in mind I am a novice sailor. I bought a used 83' for 800 with trailer. Everything seemed fine when I bought it. The guy I bought it from wasn't an experienced Hobie sailor and neither was I. After about a season of sailing she started to develop soft spots on the starbord bow. Unfortunately it was probably of my own doing since I hadn't discovered this awesome forum at the time and even though I always drained my hulls after a sail I wasn't aware of the importance of leaving the plugs out.

, but I don't know the complete history of the boat either.
I have done the delam repair, and actually plan on adding a little more expoxy inbetween the crossbars today, as there seems to be another area of delam that I did not origianally fix. Even though I believe the repair will be solid, I will always have in my mind that I am sailing on a repaired boat. There will always be that little bit of doubt that I didn't get all of the areas or that something may happen at a critical time. Plus from what I have researced, a boat with soft hulls will tend to develop them in other areas as well. Plus it drastically reduces resale value.
So even though most will tell you to walk away that is a question you'll have to ask yourself. Is it worth saving a little on a boat that will likely require future repairs? Is it worth knowing that there is a defect in the boat? If your like me and can't afford much more it might be ok, plus you'll get to learn a lot about them from the research I'm sure you'll do on it. I can't even begin to state all that I have learned, mostly from this forum, on researching my delam repair. It's actually how I discovered this forum. So in a way it has in some way benefited me. But if I would have known what I know now back when I bought the boat, which was the most I've ever spent on anything besides tuition, I would have looked for a more solid, newer boat even if I had to save up a little longer. I just can't wait until I'm able to get a brand new one and don't have to have the uncertainty on my mind. The quotes I got for professional repair were more than I could swing.
Sorry for rambling, hope this helps. Please correct me if I may be wrong, experienced please chime in.
James