Every quote and travel cost rolls into one budget that's always current. Swap any quote and the entire budget rebuilds, so you can put the premium and the lean option side by side.
When a quote changes, the total changes with it. No 9pm spreadsheet, no stale figure when finance asks.
Change the venue and the dependent lines recalculate around it. The unrelated ones hold.
Walk in with two full options, real numbers on both, and hand leadership a decision instead of a number.
One brief in, real quotes back, one live budget you can take to finance.