Did the optician ask if either of your parents had glaucoma? If they did, or if you told them they did, then this qualifies for a free eye test. This is separate from the complex lens voucher.
I don't know the website you're getting your advice from, but once you get to this level then a bog-standard lens is going to start looking a bit like a bottle bottom, so if this bothers you you need to invest in a high-index lens which costs much more (in the UK). You will probably find if you price these up that your frames cost much less than your lenses, even if you choose a designer frame.
I think that opticians make specs pricing deliberately confusing in the UK, with many of the 'deals' being reminiscent of those sofa companies that constantly advertise amazing not-to-be-missed bargains, without ever telling you the actual normal rtail price.