The phrase "a small price to pay for salvation" suggests that there is a cost or sacrifice that must be made in order to achieve a greater good or benefit. In this context, "salvation" is often used to refer to spiritual or religious redemption, and the "price" is a sacrifice or hardship that must be endured in order to attain it.
The phrase can also be used in a more secular context, where salvation can be seen as a positive outcome, such as a solution to a problem, or a positive change in life. In this case the "price" would be the effort, the sacrifice, or the cost that needs to be made in order to achieve that positive outcome.
It's worth noting that the phrase implies that the cost or sacrifice is considered to be insignificant or acceptable in comparison to the benefits of salvation. It's important to consider the situation and the context before using this phrase, as it can be perceived as insensitive or dismissive of the cost or sacrifice required.