most people think they are good.

This. Knowing exactly where you hit with certainty makes the decision of how long to wait before going after your deer well worth the price of the nok. You'll know immediately if you hit the vitals, and won't have to guess from the split second image of where you think your arrow hit that you would otherwise have without using a lighted nok.

but it probably costs more than my unlit ones. And I sure am against price increase expenditures, especially if the old way worked.

I have tried several brands and the best one is archers flame for me.With carbon express maxima hunters the bull dog collar causes some brands not to come on very well or at all.The archers flame comes on everytime no matter what kind of arrow you shoot.Its almost like the little lights in the bobbers that push in and pull out.

Lighted nocks do have their advantages and disadvantages.
Some of the advantages are mentioned in some replies already given.
Added to those, another good thing about using lighted nocks can really guide you with your 'follow through'. Quite often enough, a shooter immediately moves his bow from anchor after the shot to see where the arrow hits...this itself will also change your intended point of aim. The lighted nock allows you to see how the arrow travels and actually will create a subconcious delay to move your bow from anchor. Another 'good' advantage when using a lighted nock.
On the other hand, some lighted nocks weigh as much as 27-28 grains, 15-16 grains more than a standard non-lighted nock, this will change your point of impact a bit if you using both standard nocks and lighted nocks in you quiver. Also the lighted nock will change your FOC a tad bit. It is best to achieve 'more' FOC, compared to 'less'...but here they are things you can do to correct this.

I shot a turkey last fall. The arrow passed through the bird and skipped off a rock. From my ground blind I could follow the arrow as it skipped through the branches. At dusk I walked right over to a little light. With the price of a Maxima Hunter plus a broadhead, the lighted nock paid for itself.

I don't and won't go into the woods without them. All of my hunting arrows have Lumanoks and I love them!!!!!!!

I have had easton tracers on my arrows for the last season.

I found that the first set had issues in below freezing temps, returned for replacements.

Last season I took 2 shots. The first was a kill shot, the tail end of the arrow broke off (vanes and knock) and never found it, so no advantage in having a lighted knock in that case.

The second shot deflected off a limb, clean miss. When I retrieved the arrow, I discovered that the battery broke off of the light, the knock was destroyed and did not light.

I plan to use them again this year, but so far they have not helped or performed as expected.

I will be picking up a set of Firenocks for a trip to Kentucky. I am impressed by their design and customer service so they get my vote.