All good arguments both ways.
Like some, I have investments and I have cash on hand for things like the OP wants to do.
Could complicate it even more with things like loss of investment interest, but at some point it’s all risk vs reward vs additional effort.
Rent = spend 9k never to be seen again, no risk, no reward.
Buy cash = risk of deprecation and repairs. Possible reward on resale , possible loss on earned interest.
Invest 70k, take a loan for rv = same as above with minor gain/risk on investment.
Easy button is spend the money and rent. Other options depend on luck and skill.