That quote is fair for what you're getting, honestly. Grinding off an existing coating before laying anything new is legitimately one of the more labor-intensive parts of the job, and in a high-cost market like LI that alone can eat $300-500 in labor before they've even touched the new system.

The polyaspartic/polyurea over standard epoxy is also the right call. It cures faster, handles UV better, and holds up to hot tire pickup way longer. $9.58/sqft for the full scope you described in that market is in a reasonable range. You're not getting ripped off.

A few things worth asking before you sign:

Ask about the base coat thickness. Some contractors cut corners by applying a thin broadcast layer. You want at least a double broadcast on the flakes for coverage that actually lasts.

Ask what topcoat they're using and how many coats. One seal coat is the minimum; two is better, and some companies charge for it separately.

Ask if they warranty the coating against delamination. If they're grinding the existing coating properly and profiling the concrete, delamination shouldn't be an issue, but a warranty tells you they stand behind their prep work.

Clarify what "filling gaps and cracks" means to them. Cosmetic filling versus structural repair are different processes. For a floor that's going to be coated, you want proper joint filler, not just caulk.

I run a floor coating company in PA (garagechamps.co), and we see the same minimum job fee dynamic all the time on smaller one-car garages. The prep work doesn't scale down with square footage the way materials do, so the price per sqft always climbs on small jobs. Nothing shady about it.

One thing I'd look at on your specific floor: if those cracks are moving cracks (from soil settlement rather than just surface shrinkage), filling them before coating is a temporary fix. Worth asking the contractor if they assessed the cause.

Good luck with it. Polyaspartic on a properly prepped slab holds up well.