This is a fundamentally flawed approach. You can’t and shouldn’t define a parameter based on ETH’s USD valuation. What’s actually happening here is simply converting ETH into LDO, so the DAO isn’t really spending anything; it’s just reallocating its assets.
That said, the ETH/LDO market cap ratio or more broadly, the ETH/altcoin ratio is currently at all-time highs. If the ETH price threshold of $3,000 is intended to time this conversion, the DAO risks missing an opportunity to convert overvalued ETH into undervalued LDO.
I see a huge misconception about buybacks in crypto.
(edit: and I also think that the excess LDO tokens held in the DAO Treasury should be burned to avoid inflating the asset, since the DAO can now maintain surplus reserves in either ETH or LDO. Spending genesis-allocated LDO tokens would be purely inflationary, while spending LDO acquired through buybacks would only create volatility without resulting in net inflation over time.)