We do custom apps...5 years is ways too long. I have never seen that..but the problem here...is a lot of "entrpreneurs have of a "good idea" but can`t tell you anything else..So does the entrepreneur get 60% of the company when the develpment team is doing 90% of the work...Which most of the time...is the truth. If the entrpreneur is tech savvy and can map out what he wants...maybe...but most of the time....not the case. The entrpreneur can hold on to more of the company if he consults with an architect first..pay for consulting blue prints...then speak to development team...but in most cases the entrpreneur won`t pay the money as it will tell him the "truth about his good idea". But if you spend $10,000-$20,000 in blue prints...it will save you development costs..and tons of money in time...in proofing your good idea. Hope this helps.
5 years is way too long. In this age of ever changing technology the website you design today will be out of sync with technology in 5 years.