When we first moved into our house we were told the driveway needed to be sealed within the first year and then every two years or so thereafter. Three years ago I went the DIY route with the initial seal. It wasn't terribly difficult but it did make a bit of a mess and I was disappointed with how long the coating ended up lasting compared to some of my neighbors that hired someone to do it for them.
This time I opted to pay someone to do it. I had discovered in the past few years that what some of my neighbors paid to have it done wasn't much more than what it cost me to do it myself. So I asked around, found a local company with good reviews, and arranged for them to come by. It ended up being about $50 more expensive than what I spent last time, took far less time, and looked nicer afterward. A crew of three showed up early one morning, cleaned the driveway, applied the coating and left, all in the span of about a half hour. As much as I prefer going the DIY route to save a bit of money, this is one I'll leave to the pros from now on.