Angel is right on the money - what you are doing at home is just as good as what you could do at the gym in terms of exercise benefits.
A lot of the benefit of joining a gym is if you want to life weights seriously, enjoy classes or are competitive (i.e. work harder when in front of others).
One more thought to help your home exercise program - if you need to challenge yourself further on toning, and in a 'good for you' kind of way, doing resistance exercise against your own weight is really good and doesn't require you to buy any equipment.
e.g. push ups, graduating from knees to toes; step-ups (use a chair) and tricep dips (you can graduate these too, by moving your legs further away from the chair).
has some really good stuff you can do at home if you want to get serious...