There are significant differences between shared hosting plans and
VPS Hosting plans and the prices reflect that, but at the end of the day they both share resources with others, but in different ways.
As has been pointed out, a
VPS Hosting is a virtual
dedicated server with its own operating system, configured in exactly the way you desire, with you having root access and (almost) total control — a shared hosting plan is nothing like this, as you can't even create reseller accounts on it, for example.
It is difficult to advise you on the best solution when we have no data to work with — you haven't stated the bandwidth you're using; the facilities of the current plan you have; the specification of the server you're on; how many sites it's hosting etc. Even if you told us in detail, the only people here that could make an accurate comparison about shared hosting plans available from eUKhost and how the servers are populated, are the staff members that frequent this forum. It doesn't get any easier with a
VPS Hosting as only staff can tell you the number of
VPS Hosting on any particular hardware node — you'd be best asking such questions in a private chat session or by PM with a staff member.
I'm sorry I can't be any more helpful at present (but I did send you a PM) ...