400 Robux costs $4.99 when you buy direct from Roblox. But if you earn it through surveys, it costs you about 30–45 minutes of answering questions — and the gamepass math works slightly differently. Here is the full breakdown.
The direct price
Roblox sells 400 Robux for $4.99 (plus regional tax). That is roughly 1.25 cents per Robux. Premium members get a small discount on larger packs, but at the 400 tier the sticker price is what everyone pays.
What 400 Robux buys
- One mid-tier gamepass (most cost 100–500 Robux).
- 2–4 avatar bundles or accessory sets from the catalog.
- About a month of small in-game purchases in most simulators.
- Roughly half of a Premium 450 subscription month.
Earning 400 Robux free via surveys
On FreeRBX, 400 Robux costs 4,000 points (10 points per Robux). That is roughly 13 standard surveys at ~300 points each, or one good partner offer plus a few quick surveys. Active users cover it in under a week — and new accounts start with a 100 Robux signup bonus, so you begin a quarter of the way there.