I used to think that my tripod was really steady until I tested it. Here's how ... using a laser pointer fixed to my telephoto lens with a spot of removable wall putty and rubber bands, I triggered the camera shutter with timer delay and observed the laser light directed onto a wall 50 meters away. The laser light vibrated, ever so slight, but enough to compromise picture detail. Even with the camera mirror locked (up), I noticed camera shake. It was more apparent at night and movement was accentuated with the mere gust of an indoor air conditioner directed at the tripod – I could imagine how much worse it would be outside in windy conditions.
Tips. For your budget, I suggest you consider a used tripod and ball head. Heavier tripods are generally steadier, particularly in winds. The best rig will dampen/absorb vibration (obvious, I know, but in this respect, multi-ply carbon fibre is superior to aluminium and is lighter). Try to avoid a tripod with a centre column – the column sacrifices rigidity, as do 4 or more leg sections. Some of the better tripods will allow you to position your camera inches above ground level yet extend to a comfortable working height for taller users.
*removed- refer to the site rules, in particular rules 3-7 for new members*