I do feel guilty for buying clones and thus causing the original developers to lose money, but when a chinese product can perform that well for a fraction of the cost, I know that money isn't going toward just materials and machining and I don't know if the product design is worth another $100 per mod.
No reason to feel guilty, they don't loose money as the originals are always out of stock, meaning there are enought customers to buy all the mods they can manufacure. In fact, having a clone to your product makes it well known.