When they do the same amount of "work" (flow), they will generally consume the same amount of electricity. That's a generalization.So do VS pumps use less electric than 2-speed always or just in certain situations?
You can look up the different pricing on the internet.How much $$ up front am I saving going with the 2-speed?
Don't overthink this too much. Both will work just fine. A 2-speed will be noticeably less front money and, therefore, pass the savings back to you quicker (over a single speed). A VS gives you some flexibility but you will pay for it in front money. It really depends on what you decide you want.