The honest comparison between a spray tan and self-tanner is not just price - it is price per day of color. A spray tan costs more up front but tends to last longer, so the two questions of “which lasts longer” and “which costs less” have different answers.
Which lasts longer
A professional spray tan usually holds 7–10 days with proper aftercare and fades more evenly, because the solution is applied uniformly and developed under ideal conditions. At-home self-tanner typically lasts 3–7 days (5–7 for premium formulas) and can fade less evenly if application or exfoliation is rushed.
Which costs less
Self-tanner wins on cost by a wide margin. A $30 bottle covers 6–8 applications - about $4 each - versus roughly $45 plus tip for a salon session. Even reapplying a little more often to offset the shorter wear, a year of self-tanning usually runs $200–$400 against $1,600+ for spray tans.
The verdict
Choose the spray tan when you need a guaranteed, longer-lasting, flawless finish for an event. Choose self-tanner for everyday color on a budget. For most people who tan regularly, the savings make self-tanner the default, with the occasional spray tan saved for special occasions.