If you're planning on keeping the RT for "some period of time", then, what does first year's, or any year's, depreciation matter?
Separately, while you may buy your home as an "investment" (though I've long thought that is not correct thinking for one's primary residence), I don't know anyone who buys any type of RV as an "investment".
They ALL cost money to buy, money to keep, money to operate, and money to maintain. But, at least in our case, it's worth what it costs.
If you're comfortable with the deal and the dealer, then ...
Cheers.