Budget a research proposal including materials.
Research budgets are built from direct costs then loaded with overhead. Staff time almost always dominates, since researcher months times monthly cost dwarfs consumables on most projects. Overhead — the institution's indirect cost recovery for space, administration and utilities — is applied as a percentage of direct costs, so it grows with everything else and must be included in the headline figure rather than discovered later.
Direct costs
Direct costs = researcher months x monthly salary cost + materials + travel and dissemination
Total with overhead
Total = direct costs x (1 + overhead rate)
Because most funders define overhead as a percentage of total direct costs. Some exclude equipment above a threshold, so check the specific funder's rules before applying a flat rate.
Open access publication charges and the final months of analysis and writing. Both arrive at the end of a grant when funds are already committed.