Well, I'd first ask what guitar you're putting it into.
In most cases I've found, it's generally a much better idea to go for the better guitar as a whole with the pickups you want. Think of it like this:
Let's say you have a Les Paul Standard Epiphone (Priced around $450) and you want to swap the pickups. You can get a chambered Gibson Les Paul Faded Studio for $800 new that has the pickups you'd want (actually better IMHO with Burstbucker Pros, the same ones they stick in Gibson Les Paul Standards these days, go figure), that plays better, and is made better to suit those specific pickups.
So, you can either sell your epiphone for about $300, and possibly pickup a used Studio for about $600, or get a new one for $700 + Tax if you take advantage of promotions that most guitar dealers have (Guitar Center has one about every week or so, it's kinda nuts).
So, instead of spending money for the new pickups + The costs to get them properly installed, I would suggest save a little more and get a better guitar that already has them installed and built for that guitar. Not to mention, the Gibson will sound and play much better than any Epiphone, and that's disregarding the pickup difference.
Just my two cents with the whole "swap out pickup" discussion. The only viable situations I see for pickup swaps are for higher end American models, as you're going to be dealing with guitars that don't have such immediate upgrades, not to mention larger price gaps.