The real question though, is do you want to just get on and ride or do you want to have the experience of building your bike up. A restoration inevitably costs more than a restored bike. Then there is the middle ground, a used classic with plenty of pattination. The needs a bit of fettling to the carbs bikes can be worthwhile if you want to get your hands dirty but probably if you prefer to just ride then theres not likely to be much saving cash wise over a good running example once you've replaced various bits that need it and there is still your time to take into account. Remember a good bike at 2k is probably going to be on good tyres and have reasonable brakes, chain and sprockets if you shop around a bit, the one that's neglected and has gummed up carbs will probably want all that buying for starters. On the flip side if your aiming to restore to showroom than you'll be replacing so much in any case plus ripping it all to bits a rougher start point and have more pennies for the restoration might be the way to go.