Piru, it's really up to you whether or not you buy one before you leave or pick it up along the Way.
All along the Camino you will find sticks being sold, beautiful palos, and buying those helps support the people who live along the routes.
But other people take walking sticks like the one you posted. (Except I really don't think you need the knife!)
It's really a matter of preference.
Last trip, I bought a palo for under 5 euros in St. Jean.
This trip, I'm taking Leki walking sticks because I'm taking a screen tent that requires sticks for setup.
Mostly the sticks are good for keeping your balance on some of the more steep trails (up and down) and for crossing water. At least that's how they helped me. I understand they're good for dogs too, but luckily no dogs attacked on my Camino.
On my practice walks around the UK I borrowed or tried a variety of sticks. 'Walking poles' I felt were not up to the task. I wanted something I could put my weight on if necessary. I ended up with a long shepherd's crook from a high street tobacconists! Cut to length (forearm straight from elbow), fitted with a reinforced rubber end and used with the opening forwards it was ideal. I carried it 662 kilometers round the Norte and Primitivo and I literally could not have managed without it.
For anyone who feels that they need a 'pole' I would I would suggest trying and buying before you go! Youngsters may cope, but for those of us who are older, stiffer and less flexible it makes sense to be prepared!
I too had "Pacer Poles" when walking from Le Puy and sing their praises!
A word of explanation to the uninitiated though - these poles are a different shape to the normal walking poles and a different technique is required to the nordic type poles that I saw most Europeans using in 2007. They have been ergonomically designed by a phsio who has (I believe successfully) attempted to design poles which can be used day after day without the arms, and more importantly the wrists, getting tired - and worse having RSI set in. The whole swing of the arm is utilised to propel one along with Pacer poles and there should be no alteration in the natural hand and arm movements if being used correctly.
I remember meeting a man (from Belgium - others may have met him too) pushing a cart over the Pyrennees in 2007 who was quite insistent that I was using my poles incorrectly. He would not listen to my attempted explanation that they were different to the normal poles and that I had been successfully using them since Le Puy. Sadly the only way to escape was to be rude and push on ahead, but he was not prepared to listen to my explanation - I could see his logic for the normal poles but the "pacers" are a different style. Cheers, Janet
There was an article on the Aladdin poles, which actually elevate you magic-carpet style, completely eliminating stress on knees and ankles. I am Googling them now, and will post the article when I find it. I hope it's not just an advertising gimmick.
I have to go with Susanna and Janet's recommendation - I used Pacer Poles and, if not for them, I would have had to abandon my walk within 3 days of starting. As someone posted last year, he'd jumped out of an airplane, white water rafted down a dangerous river, but would never take the risk of walking the camino without walking poles! I walked a week with someone who just had a stick she'd found along the way, and her walking stick didn't make the grade when we were clambering down slippery slopes, the way my walking poles did. Check out their website before you decide not to take anything. cheers, jane