Howard5252 wrote:
Lenses today are generally better than we are. If you can afford the extra money for the faster lens - buy it, you'll feel better and will not have that nagging feeling that you should have spent the money.
Sometimes even when buying things that are not a lense this happens. Buying short of one's actual equipment requirements is not good. That means you buy once for the equipment that doesn't really meet your needs, and then buy again for the equipment you should have got in the first place. Buy first to truly meet your needs. If it happens to be cheaper than the most expensive, you have had a run of luck.