Be aware that ultralight trekking poles do not handle the abuse that heavier ones can.
If you tend to use your poles for full support in a fall, you can break them. I have broke many, but I use my poles much harder than most.
The ultralights are good for people who don't put all their weight on there poles and maybe only use them as extra legs on slopes or stream crossings
I have had very good luck with the least expensive Campmor/Komperdel poles. They are as light as most $100 poles and have proven to be very durable.
They do slip out of adjustment from time to time, but it is a gradual slip over several hours, so not a problem at all.
I do not recommend the inexpensive Campmor/Leki poles. The tips are tempered steel and wear out much quicker than carbide. Also, the click lock joints make an annoying clatter when you walk. This is probably good when you don't want to surprise any bears on the trail:-)