I recently looked into this for a commercial client who wanted to budget for doing under cab lighting in about a 100 kitchens next year. Ended up installing 4 different versions of lights as a trial and cost eval between now and then. Standard puck light set up, standard halogen bar set-up and two versions of LED strip lights.
I've always hated puck lights. Just don't like the stupid, cheap little things. Halogen bars, nice good light, too much energy and heat. Both have the expensive short bulb life and replacement issue. Bulb replacement cost and maintenance personnel cost to replace bulbs has become a budget issue for the client. We installed two versions of LED lighting that were both line voltage. Lighting is pretty good on both. We'll see how they last between now and spring.
I would agree with others that LED is the way to go. Costs will be higher no matter what, going LED. If you have the time to do the research and find the products, you should be able to manage Ok though on cost. If you need the stuff tomorrow, you're screwed on cost.
There's a company in Mokena just outside of Chicago making LED bars and tape I looked into. Nice product, decent pricing. Can't find their brochure right now though.
Another option is rope lights. I love rope lights. I know some people think they are cheesy but I've found them to be very reliable, cheap cost and really versatile. I've put lots of it in and never had a call back.
On a side note, went to Lowe's the other day. They had a bunch of LED light bulbs on clearance for $5 each. HD or Menards had the same bulbs going for the regular $30-$40. Don't know if other Lowe's are doing the same.