I would certainly advise any young person starting out to think of using the budget approach to their first website. Unless you need a very high-tech database driven website, then the Mr Site package is perfect for the majority of start-up businesses who just need a www shop window.
I know that peope in the IT service business don't like the Mr Site approach and will slag it from all angles, but it delivers what to my mind is fantastic value to new businesses at a time when they need to keep funds for more important things. In the event that the business grows, they can then afford to spend lots of of money on a fancy site. The biggest killer for new businesses in early stages is cash flow, so this approach is a no-brainer to some extent.
As for the expensive website designers, I have seen the track record of many of these and it leaves a lot to be desired. The ones with the technical competence seem to have no design flair, and vice versa (I know I'm generalising, but just look at any website you like and consider if the end result was worth maybe ten grand). These companies promise much and deliver little in many cases, often take months longer than planned, and then leave the site in such a way that they have to be called back to make even slight changes. They also tie the clients into expensive hosting and other hidden costs.
In the case of Mr Site (again, I hold no brief for them, they are a UK company and I know nothing about them), they proivide anyone on a limited budget with the possibility of getting their site up and running on the same day, at a tiny cost, and the business owner can make all the changes he or she likes without incurring fees. As another poster pointed out, they also include payment options for people selling online.
I think that the only people who will have a problem with Mr Site will be the people selling the more expensive options. In addition, the only people who will notice anything "cheap" about a Mr Site site will be those same IT bods; the majority of people will visit these sites and not notice that they cost less, nor will they care. As long as a website is easily navigable, and has the necessary information, it is ok with most people.