I mostly shop online out of convenience: I don't need to go to one or several local shops to find what I want, and spend a lot of time on it. So it wouldn't change anything for me. Also, I'm from Europe (now in the US), and I'm used to paying sales tax with all the online shopping I do. Just, well, sometimes more or sometimes less depending on where I live. But, another factor to take into account might be the price; if it's something really expensive and the difference with or without tax is huge, I might think about it.