No. I'd stick to the ones you already own. The four extensions you mention don't have any discernable value. Any sales you might see are an aberration rather than the rule. You're likely to lose money for sure.
.eu i would still incline towards, depending upon what's available. I have seen some businesses migrating to .biz, .info i have seen very rare but majority are informative sites or blogs or journals and .co is not that bad either. But it all depends upon availability of the name. The domain game surprises you sometimes so you never know. It depends upon the end user however if you think the name has some value or would have some value in future than go for it! There is no harm in trying. Just give it a good long thought and choose wisely and invest less to start with.