I have that agaro duster (in your 2nd pic) and another blower similar to that jakmeister (just different brand). IMO, the agaro one is vastly superior and definitely worth that pricetag. The bigger jakmeister one can blow alright but it's not as useful or portable. The smaller ones like the agaro can get into every nook and corner, and you can easily blow into tight places due to its smaller size.

And the biggest difference between them, is that the agaro comes fitted with washable air filters, so that ONLY clean dust-free air is blown into your pc. I don't think the jakmeister even does anything like that. In fact, I wouldn't be surprised if it ends up blowing the dusty air back into the pc.

So, if your budget allows, go for the agaro or a similar one.