Geico offered $1,800 in diminished value on my 2023 Honda Accord Touring after $19,400 in rear-end repairs (8k miles, Virginia) - is this lowball and what comp data do i need to push back?

looking for some sanity check from anyone who has actually filed a DV claim and gotten paid. my 2023 honda accord touring, just under 8k miles on it when it happened, was rear-ended at a stoplight in fairfax county virginia about 9 weeks ago. the other driver was a geico insured, 100% at fault, no question on liability. the impact crumpled the rear bumper, pushed the trunk floor up, bent the rear crash bars, and there was structural work on the unibody behind the bumper. shop wrote the repair at $19,400 and geico paid it without much fight.

the car is fully repaired now, drives fine, but obviously it has the carfax accident report and any future buyer is going to discount it. virginia is a third party DV state so im entitled to file against geico for the loss in market value. i filed the DV claim about a month ago using the 17c formula as a starting reference, sent them the carfax, the repair invoice with the structural work line items, and a basic comp set. their first offer came back yesterday: $1,800.

that feels really low to me. this is a $39k touring trim with adaptive cruise, head-up display, the bose audio, the leather, the whole package. low miles. now it has a 5-figure structural repair on its carfax. i talked to a local independent appraiser who said he typically sees DV settlements on similar vehicles in the $4,500 to $7,500 range, and he charges $450 for a formal appraisal report.

questions for anyone who has done this: (1) is paying $450 for an independent appraisal worth it or is there a cheaper way to build a comp set that geico will actually take seriously? (2) virginia statute of limitations on DV claims is 5 years right? so i dont need to settle quickly if im close to a fair number? (3) anyone who fought a geico DV offer specifically, what worked? did you have to threaten small claims or did written pushback alone move the needle? appreciate any input.