Free: Contests & Raffles.
The shorter "Harris" type bipods are worthless where I hunt but some of those taller ones would be nice if you want to lug around the weight. I find if you have time to set up bipod you probably have enough time to find a tree or stump to use.
I use a fixed Harris 13.5" to 27". I mainly hunt eastern wa so most shots are sitting or kneeling or on my belly. The 13.5 gets me above the grass and if I need to get higher I'll extend it. Out of 10 deer, I've shot 8 of them off my bipod. I'd say I've come to rely on it. it comes second nature as soon as I see an animal, the bi pod comes down.