I think the answer to the OPs question depends on what type of builder you are:
There are two types - those to whom $3900 is relatively minor in the grand scheme of things and will glady pony up for just about every option - and those who have to (or choose to) make careful judgements about where to spend their limited resources. There is nothing wrong with being either type of builder, but these sorts of questions invariably result in responses from both types.
If it were me and I were still building, I would consider where else I could use that $3900 - upgraded avionics, paint, engine upgrades, etc, and would probably defer. But then I very rarely fly on grass, and when I do it's good grass (think Triple Tree), and I have a light airplane with not too much weight on the nosewheel. I did transition training in an RV6A that has spent its whole, tough life, on a rough grass strip, so I know the design is reasonably sufficient when handled appropriately. That being said, if I were based on a grass strip, or planned a lot of rough-field operations, I would spring for the upgrade (or more likely build a tailwheel), otherwise I'd pass and spend the money elsewhere. My nosewheel pops up almost immediately on takeoff roll, and stays up on landing until almost walking speed.
There may be a slight resale hit far in the future, but that's future money vs money in your pocket now. Invest the $3900 and sell in 10 years and I bet you come out on top. Or put the money towards OTHER things in your airplane that also improve resale (interior, paint, avionics, etc). Or if you can spend $3900 without much worry, go for it and enjoy the improved piece of mind.
Chris