Just for an initial cut hire from fiverr.com .u only invest 5 quid
I used Fiverr to make an animated explainer video a couple weeks ago with professional voice over. Was only $300 + Fiverr fee for a woman out of Israel. I did the storyboard as no one knows your story better than you. They did the rest within about a week and I had her make two revisions. Easy to work with and did a good job.
If you want actual video, high quality ones around here start about $5K and skyrocket from there. Of course their are lower budget providers, but you get what you pay for.
make a PPT with a simple voice over and show it to a few people outside your business area of focus (the further out the better) and play it for them and make sure they "get" your point. The video will make a pretty presentation of your ideas, so you need to first start by confirming your messaging is on point and intuitive.
Check out http://follr.com/ it's got quite a few options in one place.
i am available , to work with you i am freelancer artist making videos animation