The ACA marketplace is, as David Anderson says, a county-by-county story. Markets vary widely, or wildly, by location, sometimes down to the zip code. The variation grew positively freakish after Trump cut off CSR reimbursement and insurers responded by silver-loading -- that is, concentrating the cost of CSR in silver plans only (see below for an explanation).
There are counties (like Alfalfa in OK) where anyone with an income under 400% FPL can get a gold plan (deductible $200) for free, but where a 40 year old with an income just over the line will pay $433 per month for the cheapest bronze plan (deductible $5,000). There are counties where no one with an income over 200% FPL can get a silver plan with a deductible lower than $4,000 (Penobscot, Maine). There are counties where premiums for the unsubsidized are relatively low but silver loading has yielded no significant discounts in bronze or gold (Essex, NJ). There are counties where a large gap between the cheapest and benchmark (second cheapest) silver plan render CSR-enhanced free or close to it to most with CSR-eligible incomes, but with no affordable gold plans for those eligible for weak CSR or no CSR (Atkinson, Georgia).
This is all testament to the flawed design and inadequate funding of the ACA marketplace, as well as to the sabotage inflicted on it in the Trump era and prior. Compare Medicare/Medicare Advantage, where a monster public option, heavier and more uniform subsidies, tight constraints on provider payment rates in the private plans, and better benefit standardization create a market that's confusing enough and has large coverage gaps for many but still provides more uniform, adequate and affordable coverage than does the marketplace. (Though the marketplace actually offers more comprehensive coverage to those with incomes under 200% FPL who access CSR.)
All that said, there's a sort of broad middle of silver loading effect, in which bronze and gold plans are cheaper relative to silver than they were pre-2018. For a solo 40 year-old with an income of $24,000, or a bit under 200% FPL, a mid-range silver load effect might create a spread of over $100 per month between the cheapest bronze plan and benchmark silver ($129 per month at this income) and of less than $30 per month between the benchmark and the cheapest gold plan, i.e. up to around $160/month.
There are counties (like Alfalfa in OK) where anyone with an income under 400% FPL can get a gold plan (deductible $200) for free, but where a 40 year old with an income just over the line will pay $433 per month for the cheapest bronze plan (deductible $5,000). There are counties where no one with an income over 200% FPL can get a silver plan with a deductible lower than $4,000 (Penobscot, Maine). There are counties where premiums for the unsubsidized are relatively low but silver loading has yielded no significant discounts in bronze or gold (Essex, NJ). There are counties where a large gap between the cheapest and benchmark (second cheapest) silver plan render CSR-enhanced free or close to it to most with CSR-eligible incomes, but with no affordable gold plans for those eligible for weak CSR or no CSR (Atkinson, Georgia).
This is all testament to the flawed design and inadequate funding of the ACA marketplace, as well as to the sabotage inflicted on it in the Trump era and prior. Compare Medicare/Medicare Advantage, where a monster public option, heavier and more uniform subsidies, tight constraints on provider payment rates in the private plans, and better benefit standardization create a market that's confusing enough and has large coverage gaps for many but still provides more uniform, adequate and affordable coverage than does the marketplace. (Though the marketplace actually offers more comprehensive coverage to those with incomes under 200% FPL who access CSR.)
All that said, there's a sort of broad middle of silver loading effect, in which bronze and gold plans are cheaper relative to silver than they were pre-2018. For a solo 40 year-old with an income of $24,000, or a bit under 200% FPL, a mid-range silver load effect might create a spread of over $100 per month between the cheapest bronze plan and benchmark silver ($129 per month at this income) and of less than $30 per month between the benchmark and the cheapest gold plan, i.e. up to around $160/month.