The method for getting the best from $35K would be to add to the Real Estate, if a addition can be had for that outlay.
The method for getting the worst from $35K would to be spend it all over a short duration and on New Model Equipment.
With this type of Budget there are substantial quality used products that can be considered, from Brands that other Competitor Brands more expensive New Models, will struggle to match in SQ.
The performance that can be attained from a used item, at a very attractive VFM and the potential that the depreciation is already maximum, leaves a lot of remunerated funds to replace the original purchase price at a later date.
I would be much happier having a Item that WOW'ed others and then myself and sold after a few years of my ownership as a 5-10% depreciation, as it is still remaining sought after in the HiFi community. Maybe a Appreciation in value is being realized, as has with many of my purchases.
This would be better for my mental health, than purchasing New and when the resale time comes, it is a item not sought after and a 50%+ depreciation is to be met.
It is a Hobby after all, and upgrades does not necessary mean a New Off the Shelve Device, which might be simply a re-jacketing of a Older Technology is the requirement to improve on a already owned device.