Regarding the extra equipment, I think that all
depends on what you have. I have all of Cathe's workouts, so I have all of the equipment that is needed for her workouts. So the only thing I really needed to buy was resistance tubing for the chin-up/pull-up option. But I had the ankle/wrist weights (which I use to help with my weight increments), the resistance bands, the steps and benches, the stability ball and all the weights necessary. I even had paper plates lying around the house! So if you are already well-equipped, you may not have to purchase a thing.
Regarding the weights specifically, to give you an idea what you might need depending on your strength, I have weights from 3lbs to 35lbs (dumbbells) and do all of my weight workout with dumbbells. I may need to do something to get a dumbbell up to 40lbs for later on in the series (for rows and such), but I'm waiting to see if that is necessary. I may also purchase a weighted vest for later in the series, but I'm waiting on that as well to see if it is necessary. But the set of weights I currently have are the same weights I've needed for other Cathe programs (I use two 35lb dumbbells for legs in S&H), so, again what you may need all depends on what you can lift and what you have available.
But don't let the equipment scare you off these DVDs. Chances are even if you do need heavier weights for the latter mesocycles, you can probably do mesocycle 1 with what you have (since it is endurance based). And I firmly believe that everything and anything can be modified and still be effective, so if you need to do dumbbell rows (as an example) because you don't have resistance tubing or a chin-up bar, you are still going to be working your muscles. And that's good!
ms71069, I'm thinking you should move your birthday from July to April and buy these puppies now!