Always, always, always have a professional inspection. AS-IS means the seller will not do any repairs, but you as the buyer need to know what you are buying. I tell my buyers to consider the report from the inspection a "Honey Do List". A good inspector will usually have quite a list of items especially when you are not purchasing a "new" home. However, the inspection is needed to make sure there are no major items of concern. Sometimes you can go back to the seller, and renegotiate, but do not plan on that option. Your Realtor can give you advise. Please do get professional inspections: pest, home, roof at least.