Many countries with socio-economic problems that need to be addressed spend some of their money on weapons. As soon as you accept that Venezuela has any legitimate reason to buy arms, then you accept that some level of military spending is necessary. The question becomes one of how much military spending is justifiable, which is a question that can only be answered by, in part, looking at how much money is available to spend. This is why considering military expenditures as a share of GDP is important, and also why considering whether these expenditures (a lot of capital expenditures, as I understand it, to make up for the declining useability of US weapons systems since further arms exports to Venezuela are now blocked) are 'one-offs' or continuous (the amortization question).
If it's 'not your bag' to hazard a guess as to what a reasonable level of GDP to spend on arms would be for Venezuela, then I have a hard time taking your assertion that Venezuela is spending too much at face value.
I hope this comment isn't coming off as rude or anything.
Cheers!
CS