Cost of wiring the pickups will vary from country to country, and depends on how tidy and/or quick your tech works.
On average it'll be €25-€30 per pickup, although most shops will do 'package deals'where you pay less if you get a set and buy the pickups from them, or if you get two or more installed at the same time.
I'd not blindly go and buy ANY pickup though, i'd really read up on brands, types etc.
Suggestions, ranging from cheap to 'boutique' (aka expensive as xx--xx);
First we have
http://www.irongear.co.uk/ a set of these would cost you as much as, or sometimes less than a single Seymour Duncan, and quality has been reported as good to great, i had a set of Metal Machines in a cheap Les Paul clone, did fine for gigs where i didn't want to bring my more expensive guitars.
There's also Bulldog pickups, which are in a close price class, but the official site seems to be down for me, so here's their facebook page :
https://www.facebook.com/pages/Bulldog-Pickups/Bulldog is run by an apprentice of Tim Mills, who's company you'll see listed a little further down.
Then there's the big brand names,
http://www.dimarzio.com/ ,
http://www.seymourduncan.com/ ,
http://www.emgpickups.com/ , varying prices and varying choices, generally more expensive, but very tried and tested, not as expensive or as special as boutique stuff though, and generally less customisation possible, in case that's your thing.
And then we get to boutique, with pricerange to boot;
First off,
http://www.lacemusic.com/ the (in)famous lace pickups, well known among Fender owners for their Sensor pickup line.
Not my choice of pickup, tone wise, but very decent.
Then we move on to
http://www.fralinpickups.com/ , also very well known, and very pricey, but worth it to some.
And on to
http://jbepickups.com/ , don't have much experience with these, but The Boss used (and perhaps still uses) Joe Barden pickups, and that seems like a good enough recommendation in my book... YMMV though.
And then we got to the last one i'll mention here, and still my personal favorite, despite their VERY heft pricetag :
https://www.bareknucklepickups.co.uk/Run by Tim Mills (told you we'd get to him

), they were one of the first boutique pickup companies to do a rather broad range of pickups suited to all styles, and in contrast to some other companies, their staff is more than willing to give you suggestions based on what you're looking for, and you can even ask the man himself, he may take a (work)day or so to respond, but i've yet to see him not answer.
They're expensive as hell, handmade to order if ordered directly, often hard to come by unless you order directly, and despite all that, i'm still the proud (and happy) owner of two of their sets, where i've gotten rid of plenty of other pickup brands in the past.
Of course, i'm a 'tone snob' according to some, so caveat emptor
