For the love of Saint Pete, PLEASE do NOT boost posts. If your objective is to produce a sale, the last thing you should be doing is boosting your post.
Let me explain why..
Facebook is a learning algorithm. It works on a the premise of delivering content to those that meet a specific objective you specify. When boosting posts, the primary objective is post engagement. So Facebook goes out and finds others who are likely to meet this objective.
Nine times out of ten people who like, share, and comment are only partially interested in whatever post you BOOST. Most of them are not interested enough to submit their information, and in the event they do they tend to go MIA.
Here's what you should do instead..
1: Stay as far away as you can from Lead Ads. A lot of the information people submit via a lead ad is outdated, since Facebook auto-populates the form for the user. Also, people tend to submit their information by accident. Which can lead to a lot of confusion.
2: Build a funnel/form, and send people to this through a conversion ad. For example, here's one of my clients forms. Make sure a pixel is installed, and a custom conversion objective is specified on the second page.
3: Build a campaign with a Conversions objective through the ad manager. And ensure you speak to your audience and target them at a specific angle. In my unique instance, one of my newest clients and I are running a Uber Driver offer. Exact ad copy & creative are posted below:

The result's we're getting:

Appointments we've scheduled so far:

It's through the campaign structure we're using that we've had as much success as we've had. Although I don't recommend replicating the exact campaign verbatum, I do suggest you find a unique way to target your audience.
Lastly: DO NOT USE INTEREST BASED TARGETING.
Keep your targeting as open as possible. Only narrow down your audience size using look-a-likes, nothing else.
Again, Facebook is a learning algorithm. So it needs data and TIME to achieve whatever result you desire. In my instance, it's an appointment. Which converts to a sale 1/8 times.
Should you have any questions feel free to post below. I'll be posting a massive tutorial on Facebook Marketing very soon, so please keep your eyes peeled.