This is not fiscally intelligent.
For those of you who have $100 to spend and are interested, Permanent Accounts are on sale right now. They go on sale intermittently. That's how I got mine - in the previous sale, last March. For $100.
By contrast, buying Paid Account time through the year 2021 will cost you $475 and will give you less perks for your money.
Of course, if you're poor, you could also try to earn a permanent account for free by helping out with LJ administration, such as answering questions in the support forum. But I never seem to get awarded points for even half the questions I answer in the support forum, so I think it would take a distinctly long time to earn a free permanent account that way.