Purchasing a font family is a great choice if you really want to maximise the design options with a font that you love.  Plus, our foundry partners usually offer these at a huge discount, compared to purchasing individual weights.   We do not offer a discount if you have already purchased one weight, but we know that this sometimes occurs, so you should find that in 99.9999% of cases you will be saving more than the cost of your one font weight, when you do purchase your family (compared to buying each individual weight or style).   Each foundry and family pack is different, so you will need to do the math with the styles and weights you think you need.  But, quite often, the family pack will be the logical option.