Here we go again with the 'if you have to finance it you can't afford it crap. If the OP wants to spread the payments over 3 years to make it more affordable and can afford to pay £45 a month without worrying, then where's the problem? sure, he'll pay interest but he knows that. Sometimes it is easier to pay £45 a month rather that a couple of grand in one shot, it's less of a hit, it doesn't mean he can't afford it!
Why pay more than you absolutely have to? The advice is sound and technically, if you need to use credit for anything, you can't afford it