upgrade navision 3.7 to navision 13 r2

Upgrading Navision 3.7 to Navision 13 R2. Kindly sugest ?

Upgrading from 3.7 version to NAV 2013 R2 will be tedious process as there is no direct process available for the same (i.e Upgrade Toolkit) so need to upgrade version by version .

I suggest It is better go for new implementation rather than investing time in upgrade.