My recommendation with "economic customers" is minimize you're efforts significantly. For instance, I would do a wash, DA polish with KAIO, and top with ZCS. $99 for the exterior done in about 2 hours = $50/hour. Then I'd try to upsell a clay for an additional $24.99. Notice I'm not bothering with "filling." Honestly, most customers I dealt with never even realized the scratches and swirls were and issue or part of the detail.
If your customer doesn't care, save your effort.