A great set of Rock Shocks can set you back $600 to sky is the limit in the $1000's. Lately I've given up on the cheapest bikes, parts are exactly that, cheap and they break. Anyways I try to stick to a name brand bike like Trek, DB or ?, used or new. If new the lower end models. The forks they have I've never had issues with hoping the quality is better. I would never buy a bike w/o shocks on the front. When you ride you can feel the shocks absorbing a lot of bumps that don't transfer to your back. I'm still working on a seat post suspension that doesn't cost over $100 and works. Some shocks you can lock so there's no movement, some have adjusters for dampening strength, some are gas charged while lower end units use springs, some are hydraulic. My only experience is with the stock shocks the bikes come with and usually have springs. They work great bubba!