To be honest with you mate, people are really tired of this long term vps contract because it often disappoint without any warnings and every data/information kept on it shall no longer be accessible.
You will need to give a concrete assurance/proof that this product will last as you promised and mention the country(ies) you are selling.
i have sold more then 5 vps.
its more then 3 months now all vps are working fine , i myself and my clients did not got any issue till yet.
but if you want monthly vps then i can also provide you monthly vps.