A 28-year-old married woman from rural Maharashtra attends the primary health centre for family planning counselling. She has completed her family with 2 children (ages 5 and 3 years). Her husband is a daily wage labourer with irregular income. She is breastfeeding her 3-year-old child and reports irregular menstrual cycles. On examination, she is healthy with no contraindications to hormonal methods. The health worker discusses various contraceptive options including oral contraceptive pills, intrauterine devices, barrier methods, and permanent methods. The woman expresses concern about cost and compliance. Which contraceptive method would provide the best balance of efficacy, cost-effectiveness, and suitability for her current clinical and socioeconomic context?