You might think
anything will be a step up from what you have, but you also have to look at the application. Is this for live or....... home recording? Oh, the irony. Anyway, if it's live, you won't notice a huge difference until you spend $$$. If it's for recording, you still may not notice night-and-day differences. If you're using them raw, maybe. But once you get into pres, EQ's, compressors, and what have you, it will all affect what you end up with, not just the mic alone. I have a few drum mic packs (I'm a slooooooooow learner), and the kick mic always comes up short on the cheap packs. If you get
the Audix DP5-A kit, you'll avoid being dissapointed, and you'll avoid having to buy a separate D6.
The truth is I wouldn't avoid anything, but I know I'll always have to add a D6, so just get the Audix pack right off the hop. If money is a big issue, the CAD Pro-7 is $200, the Audio Technica MB/DK4 is $129, and Superlux maybe the same. The D6 alone is $200, so there goes the budget. And they may all sound the same as your Samson, so whaddaya gain? Maybe just try a D6 instead of what Samson gives you, and save some time and money. Now add EQ and compression, and you may be pleasantly surprised.