Is it safe to use both the pump and extender

Is it safe to use the extender and pump together?

for example to use the extender throughout most of the day.. and then use the pump that same night? To what degree would it be safe, or be considered unsafe?

are there any discounts if i buy both kits? Im considering getting the pump also to complement the extender as an immediate enhancer. Thinking about getting a breast pump kit as well, so Im looking to put down quite a bit. Are there any discount programs to help ease the financial strain?.. or complimentary accessories to at least get the most out of all these products for the best results? Or should I just get one kit first, see how I like the product before I pull the trigger on buying more kits since they're all after shipping priced, so it's not like i save on S&H anyway