Don't feel guilty, I am green with envy and wish I had several readers! You don't have the hassle to convert to this or that format and you get to try nifty gadgets. Plus, imagine you get a house guest and don't have an spare ereader to offer. What kind of hospitality is this? I'd be appalled. The horror!
In any case, I think it's common sense having a go ereader and a ereader with a bigger screen to use at home. I am thinking of buying the Pocketbook 903 when it comes out if it is soon enough. Or the Kindle DX, if the Pockectbook is not out by October. Or both. Heir and spare indeed!
Some people are nuts for cars, TVs, gaming systems, clothes or travel extensively every year. That's OK, it's their thing. Whatever makes you happy and you can afford, of course. We are nuts for ereaders. So what? Is reading such a shameful habit?
. My Gran used to think so.