Filing fee plus service, by state — with the official source and the verification confidence for every figure.
Filing fees in small claims court are low by design — most states charge somewhere between $15 and $150, usually scaled to the size of the claim. The costs people miss are the ones after filing: serving the defendant, serving each additional defendant, and re-serving when the first attempt fails because the address was stale.
Service is the single most common place a small claims case stalls. A defendant who cannot be found cannot be served, and a case that cannot be served cannot be heard. Budget for a second attempt.
Every state has a process to waive filing fees for people who cannot afford them, usually keyed to income, household size, or receipt of public benefits. It is a routine administrative form, not a favour, and the court cannot charge you for filing it. If money is the reason you have not filed, ask the clerk for the fee waiver form before you decide the case is not worth bringing.
Usually, in part. Most states let a winning plaintiff recover court costs — the filing fee and service costs — on top of the judgment. What you generally cannot recover is your own time, and in most small claims courts you cannot recover attorney's fees because attorneys are often not permitted in the first place. Winning a judgment is also not the same as collecting it, which is a separate process with its own costs.